Tag Archives: low-carb diet

August 13, 2010 · 8:16 AM

Is a Low-Carb Diet Safe For Obese Adolescents?

High-protein, low-carbohydrate diets are safe and effective for severely obese adolescent, according to University of Colorado researchers.

Childhood obesity in the U.S. tripled from the early 1980s to 2000, ending with a 17% obesity rate.  Overweight and obesity together describe 32% of U.S. children.  Some experts believe this generation of kids will be the first in U.S. history to suffer a decline in life expectancy, related to obesity.

Colorado researchers wondered if a low-carb, high-protein diet is a reasonable treatment option.  Why high protein?  It’s an effort to preserve lean body mass (e.g., muscle). 

ResearchBlogging.orgThey randomized 46 adoloscents (age 12–18) to either a high-protein, low-carb diet (HPLC diet) or a calorie-restricted low-fat diet to be followed for 13 weeks.  HPLC dieters could eat unlimited calories as long as they attempted to keep carb consumption to 20 g/day or less.  Low-fat dieters were to choose lean protein sources, aiming daily for 2 to 2.5 grams of protein per kilogram of ideal body weight.  Study participants underwent blood analysis and body compositon analysis by dual x-ray absorptiometry.  These kids weighed an average of 108 kg (238 lb) and average body mass index was 39. 

Analysis of food diaries showed the following:

  • Average caloric intake was 1300-1450/day, toward the lower end for the HPLC dieters
  • Energy composition of the HPLC diet: 32% from protien, 11% from carb, 57% from fat
  • Energy compositon of the LF diet: 21% from protein, 51% from carb, 29% from fat
  • Average daily carb consumption for the HPLCers ended up closer to 40 g (still very low) 

Findings

Both groups lost weight, with the HPLC dieters trending to greater weight loss, but not to a statistically significant degree.  They did, however, show a greater drop in body mass index Z-score, however.  Study authors didn’t bother to explain “body mass index Z-scores,” assuming I would know what that meant.  Average weight in the HPLC group dropped 13 kg (29 lb) compared to 7 kg (15 lb) in the low-fat group.

Total and LDL cholesterol fell in both groups, and insulin resistance improved.  Neither diet had much effect on HDL cholesterol.

As usual, triglycerides fell dramatically in the HPLC dieters.

Nearly 40% of the kids—about the same number in both groups—dropped out before finishing the 13 weeks.

The HPLC group did not see any particular preservation of lean body mass, and actually seemed to lose a bit more than the low-fat group.

There were no serious adverse effects in either group. 

Surprisingly, satiety and hunger scores were the same in both groups.  [Low-carb, ketogenic diets have a reputation for satiation and hunger suppression.]

My Comments

This is a small short-term study with a large drop-out rate; we must consider it a pilot study.  That’s why I’m not as enthusiastic about it as the researchers.  Nevertheless, it does indeed suggest that high-protein, low-carb diets are indeed safe and effective in obese adolescents.  It’s a start.   

Steve Parker, M.D.

Reference: Krebs, N., Gao, D., Gralla, J., Collins, J., & Johnson, S. (2010). Efficacy and Safety of a High Protein, Low Carbohydrate Diet for Weight Loss in Severely Obese Adolescents The Journal of Pediatrics, 157 (2), 252-258 DOI: 10.1016/j.jpeds.2010.02.010

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August 7, 2010 · 2:00 AM

Low-Fat and Low-Carb Diets End Battle in Tie After Two Years, But…

Dieters on low-fat and low-carb diets both lost the same amount of weight after two years, according to a just-published article in Annals of Internal Medicine.  Both groups received intensive behavioral treatment, which may be the key to success for many.  Low-carb eating was clearly superior in terms of increased HDL cholesterol, which may help prevent heart disease and stroke.

The study was funded by the National Institutes of Health and was carried out in Denver, St. Louis, and Philadelphia.

How Was It Done?

Healthy adults aged 18-65 were randomly assigned to either a low-fat or low-carbohydrate diet.  Average age was 45.  Average body mass index was 36 (over 25 is overweight; over 30 is obese).  Of the 307 participants, two thirds were women.  People over 136 kg (299 lb) were excluded from the study—I guess because weight-loss through dieting is rarely successful at higher weights.  Diabetics were excluded. 

The low-carb diet:  Essentially the Atkins diet with a prolonged induction phase (12 weeks instead of two).  Started with maximum of 20 g carbs daily, as low-carb vegetables.  Increase carbs by 5 g per week thereafter as long as weight loss progressed as planned.  Fat and protein consumption were unlimited.  The primary behavioral goal was to limit carb consumption.

The low-fat diet:  Calories were limited to 1200-1500 /day (women) or 1500-1800 (men).  [Those levels in general are too low, in my opinion.]  Diet was to consist of about 55% of calories from carbs, 30% from fat, 15% from protein.  The primary behavioral goal was to limit overall energy (calorie) intake. 

Both groups received frequent, intensive in-person group therapy—lead by dietitians and psychologists—periodically over two years, covering such topics as self-monitoring, weight-loss tips, management of weight regain and noncompliance with assigned diet.  Regular walking was recommended.

Body composition was measured periodically with dual X-ray absorptiometry.

What Did They Find?

Both groups lost about 11% of initial body weight, but tended to regain so that after two years, both groups average losses were only 7% of initial weight.  Weight loss looked a little better at three months in the low-carb group, but it wasn’t statistically significant. 

The groups had no differences in bone density or body composition.

No serious cardiovascular illnesses were reported by participants.  During the first six months, the low-carb group reported more bad breath, hair loss, dry mouth, and constipation.  After six months, constipation in the low-carb group was the only symptom difference between the groups.

During the first six months, the low-fat group had greater decreases in LDL cholesterol (with potentially less risk of heart disease), but the difference did not persist for one or two years.

Increases in HDL cholesterol (potentially heart-healthy) persisted throughout the study for the low-carb group.  The increase was 20% above baseline.

About a third of participants in both groups dropped out of the study before the two years were up.  [Not unusual.]

My Comments

Contrary to several previous studies that suggested low-carb diets are more successful than low-fat, the study at hand indicates they are equivalent as long as dieters get intensive long-term group behavioral intervention. 

Low-carb critics warn that the diet will cause osteoporosis, a dangerous thinning of the bones that predisposes to fractures.  This study disproves that.

Contrary to widespread criticism that low-carb eating—with lots of fat and cholestrol— is bad for your heart, this study notes a sustained elevation in HDL cholesterol (“good cholesterol”) on the low-carb diet over two years.  This also suggests the low-carbers  followed the diet fairly well.  The investigators also note that low-carb eating tends to produce light, fluffy LDL cholesterol, which is felt to be less injurious to arteries compared to small, dense LDL cholesterol.

A major strength of the study is that it lasted two years, which is rare for weight-loss diet research.

A major weakness is that the investigators apparently didn’t do anything to document the participants’ degree of compliance with the assigned diet.  It’s well known that many people in this setting can follow a diet pretty well for two to four months.  After that, adherence typically drops off as people go back to their old habits.  The group therapy sessions probably improved compliance, but we don’t know since it wasn’t documented. 

How often do we hear “Diets don’t work.”  Well, that’s just wrong.

Overall, it’s an impressive study, and done well. 

Individuals wishing to lose weight on their own can’t replicate these study conditions because of the in-person behavioral intervention component.  There are lots of self-help calorie-restricted balanced diets (e.g., Sonoma Diet, The Zone,  Advanced Mediterranean Diet) and low-carb diets (e.g., Atkins Diet, Banting’s Letter on Corpulence, Low-Carb Mediterranean or Ketogenic Mediterranean Diets).  On-line support groups—e.g. Low Carb Friends and SparkPeople and 3 Fat Chicks on a Diet—could supply some necessary behavioral intervention strategies and support.  

Choosing a weight-loss program is not as easy as many think.  [Well, I’ll admit that choosing the wrong one is easy.]  I review the pertinent issues in my “Prepare for Weight Loss” page.

Steve Parker, M.D.

Reference: Foster, Gary, et al.  Weight and metabolic outcomes after 2 years on a low-carbohydrate versus low-fat diet: a randomized trial. Annals of Internal Medicine, 153 (2010): 147-157   PMID: 20679559

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May 27, 2010 · 12:31 AM

Book Review: Diabetes Solution – The Complete Guide to Achieving Normal Blood Sugars

Here’s my review of Dr. Bernstein’s Diabetes Solution: The Complete Guide to Achieving Normal Blood Sugars, published in 2007.  Per Amazon.com’s rating scale, I give it five stars (I love it).  

♦   ♦   ♦ 

Dr. Richard K. Bernstein gives away thousands of dollars’ worth of medical advice in this masterpiece, Diabetes Solution.  It’s a summation of his entire medical career and a gift to the diabetes community.  

The book starts off with some incredible testimonials: reversal of diabetic nerve damage, eye damage, and erectile dysfunction.  They’re a bit off-putting to a skeptic like me, like an infomercial.  Dr. Bernstein is either lying about these or he’s not; I believe him.  His strongest testimonial is his own.  He’s been a type 1 diabetic most of his life, having acquired the disease at a time when most type 1’s never saw 55 candles on a birthday cake.  He’s in his mid-70s now and still working vigorously.  

I only found one obvious error and assume it’s a misprint. He writes that 95% of people born today in the U.S. will eventually develop diabetes.  That’s preposterous.  The U.S. Centers for Disease Control predicts that one in three born in 2000 will be diagnosed.  

Dr. Bernstein delivers lots of facts that I can neither confirm nor refute.  He’s a full-time diabetologist; I am not.  

"Put down the bread and no one will get hurt!"

  

The central problem in type 1 diabetes is that, due to a lack of insulin,  ingested carbohydrates lead to spikes (elevations) in blood sugar.  The sugar elevations themselves are toxic.  The usual insulin injections are not good imitators of a healthy pancreas gland. So Dr. Bernstein is an advocate of low-carb eating (about 30 g daily compared to the usual American 250-300 g).  He says the available insulins CAN handle the glucose produced by a high-protein meal.  

Dr. B reminds us that insulin is the main fat-building hormone, which is one reason diabetics gain weight when they start insulin, and why type 2 diabetics with insulin resistance (and high blood insulin levels) are overweight and have trouble losing weight.  You can have resistance to insulin’s blood sugar lowering action yet no resistance to its fat-building (fat-storing) action.  Insulin also stimulates hunger, so insulin-resistant diabetics are often hungry.  

“Carbohydrate counting” is a popular method for determining a dose of injected insulin.  Dr. B says the gram counts on most foods are only a rough estimate—far too rough.  He minimizes the error by minimizing the input (ingested carbs).  From his days as an engineer, he notes “small inputs, small mistakes.”  

Dr. B also cites problems with the absorption of injected insulin.  Absorption is variable: the larger the dose, the greater the variability.  So don’t eat a lot of carbs that require a large insulin dose.  For adult type 1 diabetics, his recommended rapid-acting insulins doses are usually three to five units.  If a dose larger than seven units is needed, split it into different sites.  

He recommends diabetics aim for normal glucoses (90 mg/dl or less) almost all the time, and hemoglobin A1c of 5% or less.  This is extremely tight control, tighter than any expert panel recommends.  He says this is the best way to avoid the serious complications of diabetes.   

Here’s a smattering of “facts” in the book that made an impact on me, a physician practicing internal medicine for over two decades.  I want to remember them, incorporate into my practice, or research further to confirm:  

  • Hemoglobin A1c of 5% equals an average blood sugar of 100 mg/dl (5.56 mmol/l).  For each one % higher, average glucose is 40 mg/dl (2.22  mmol/l) higher.
  • He’s against any drugs that overstimulate (“burn out”) the remaining pancreas function in type 2 diabetics: sulfonylureas, meglitinides, “phenylalanine derivatives”.  Pancreas-provoking agents cause hypoglycemia and destroy beta cell function.
  • The insulin sensitizers are metformin and thiazolidinediones.  He likes these.
  • Blood sugar normalization in type 2 diabetes and early-stage type 1 can help restore beta cell function.
  • He often speaks of preserving beta cell function.
  • He believes in “insulin-mimetic agents” like alpha lipoic acid (especially R-ALA, and take biotin with either form) and evening primrose oil.  These  are no substitute for insulin injections but allow for lower insulin doses.  ALA and evening primrose oil don’t promote fat storage like insulin does.
  • He says many cardiologists take ALA for its antioxidant properties [news to me]
  • He says rosiglitazone works within two hours [news to me] but later admits it may take 12 weeks to see maximal benefit
  • One of his goals is to preserve beta cell function if at all possible
  • He prefers rosiglitazone over pioglitazone due to fewer drug interactions
  • “Americans are fat largely because of sugar, starches, and other high-carbohydrate foods.”
  • He’s convinced that people who crave carbohydrates have inherited the problem, which also predisposes to insulin resistance and type 2 diabetes.  Low-carb diets decrease the cravings for many, in his experience.
  • In small amounts, alcohol is relatively harmless: dry wine, beer, spirits.  Very few doctors have the courage to say this.
  • If you’re in a restaurant, you can use urine sugar test strips and saliva to test for presence of sugar or flour in food
  • A rule of thumb: one gram of carbohydrate will raise blood sugar about 5 mg/dl (0.28  mmol/l) or less for most diabetic adults weighing 140 lb (64  kg) and about 2.5 mg/dl (0.139 mmol/l) in a 280-pounder (127  kg).  This must refer to type 1 diabetics or a type 2 with little residual pancreas beta cell function; variable degrees of insulin resistance and beta cell reserve in many type 2s would make this formula unreliable.
  • Be wary of maltodextrin in Splenda: it does raise blood sugar.
  • Much new to me in his section on artificial sweeteners.  Be wary of them.
  • He avoids all grains, breads, crackers, barley, oats, rice, and pasta.
  • Most diet sodas are OK.
  • Coffees with 1-2 tsp milk is OK.  Cream is OK.
  • He eats NO fruit and recommends against it.
  • He avoids beets, corn, potatoes, and beans. A slice of tomato in one cup of salad is OK.  A small amount of onion is OK.
  • String beans and snow peas are OK.
  • Cooked vegetables tend to raise blood sugar more rapidly than raw.
  • Use “Equal” aspartame tabs as a sweetener.  Don’t use “powdered” Splenda.
  • Avoid nuts: too easy to overeat.
  • For desert: sugar-free Jell-O Brand Gelatin.
  • Yogurt?  Plain, whole milk, unsweetened.  Flavor with cinnamon, Da Vinci syrups, baking flavor extracts, stevia or Equal.
  • Avoid balsamic vinegar.
  • Need fiber?  Bran crackers or soybean products.
  • “Ideally, your blood sugar should be the same after eating as it was before.”  85 mg/dl (4.72  mmol/l) is his usual goal.  If blood sugar rises by more than 10 mg/dl (0.56 mmol/l) after a meal, either the meal has to be changed or medication changed.
  • Protein is a source of glucose: keep protein amounts at meals constant from day to day, especially if taking glucose-lowering drugs.
  • The lowest-carb meal of the day should be breakafast.  Why?  Dawn phenomenon.
  • He promotes strenuous, prolonged exercise, especially weight training (extensive discussion and instruction in book).
  • Many diabetics on insulin need dose adjustments in 1/2 and 1/4 unit increments [news to me: if I ordered 4 and 1/4 units of insulin at the hospital, the nurses would laugh].
  • Typical rapid-acting insulin doses for his adult type 1 patients are 3-5 units.  The “industrial doses” of insulin seen or recommended by many physicians reflect diets too high in carbohydrate.
  • He says Lantus only acts for nine hours (nighttime injection) or 18 hours (AM injection).
  • He doesn’t like mixed insulins (e.g., 70/30).
  • Humalog and Novolog are more potent than regular insulin, so the dose is about 2/3 of the regular insulin dose
  • “Only a few of the 20 available [home glucose monitoring] machines are suitably accurate for our purposes.”  “None are suitably accurate or precise above 200 mg/dl [11.11 mmol/l].”
  • Vitamin C in doses over 250 mg interferes with fingertip glucose monitors.  Later he says doses over 500 mg cause falsely low readings.
  • He prefers regular insulin (45 minutes before meal) over Novolog and Humalog, because of its five-hour duration of action.
  • Insulin users need to check glucose levels hourly while driving.
  • His personal basal insulin is 3 units Lantus twice daily.
  • He urges use of glucose (e.g., Dextrotabs) to correct hypoglycemia.
  • He says hypoglycemia is rare on his regimen.
  • He has an entire chapter on gastroparesis.

Dr. Bernstein’s recommended eating program in a nutshell:  

  • Some similarities to the Atkins diet, which he never mentions.
  • No simple sugars or “fast-acting” carbs like bread and potatoes, because even type 2s have impaired or nonexistent phase 1 insulin response.
  • Limit carbs to an amount that will work with your injected insulin or your remaining phase 2 insulin response, if any.
  • “Stop eating when you no longer feel hungry, not when you’re stuffed.”
  • Follow a predetermined meal plan (each meal: same grams of carb and ounces of protein)
  • Six g (or less) of carbs at breakfast, 12 g (or less) at lunch and evening meal.  So his patients count carb grams and protein ounces.
  • Supplements are not required IF glucoses are controlled and eating a variety of veggies.  Otherwise you may need B-complex or multivitamin/multimineral supplement.
  • Recipes are provided.

His has four basic drug treatment plans, tailored to the individual.  They are outlined in the book.  Dr. B provides detailed notes on what he does with his personal patients.  

Overall impressions:  

  • Too complicated for most, and they won’t give up higher carb consumption.  It requires a high degree of committment and discipline.  In fact, I’ve never had a patient tell me they were on the Bernstein program.
  • If I had type 1 diabetes, I might well follow his plan or the Low-Carb Mediterranean Diet, NOT the high-carb diet recommended by the ADA and many dietitians.
  • And if I had type 2 diabetes?  Low-Carb Mediterranean Diet first, Diabetes Solution as second choice.
  • If one can get his hemoglobins A1c down to 5% with other methods, would that be just as good?  Dr. B would argue that all other methods have blood sugar swings that are too wide.
  • Many new ideas and techniques here, at least to me.
  • He pretty much reveals his entire program here, which is priceless.
  • I’m not sure this plan will work unless the patient’s treating physician is on-board.
  • His personal testimony and breadth of knowledge are very persuasive. 

Steve Parker, M.D.  

Disclosure:  I was given nothing of value by Dr. Bernstein or his publisher in return for this review.

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May 17, 2010 · 12:22 AM

Low-Carb Mediterranean Diet Improves Glucose Control and Heart Risk Factors in Overweight Diabetics

In overweight type 2 diabetics, a low-carbohydrate Mediterranean diet improved HDL cholesterol levels and glucose control better than either the standard Mediterranean diet or American Diabetes Association diet, according to Israeli researchers reporting earlier this year.

Background

Prior studies suggest that diets rich in monounsaturated fatty acids (olive oil, for example) elevate HDL cholesterol and reduce LDL cholestrol and triglycerides in type 2 diabetics.

Low-carb diets improve blood sugar levels and reduce excess body weight in type 2 diabetics, leading to the ADA’s allowance in 2008 of a low-carbohydrate diet as an alternative to standard diabetic diets.

Many—probably most—type 2 diabetics have insulin resistance:  the body’s cells that can remove sugar from the bloodstream are not very sensitive to the effect of insulin driving sugar into those cells.  They “resist” insulin’s effect.  Consumption of monounsaturated fatty acids  improves insulin sensitivity.  In other words, insulin is better able to push blood sugar into cells, removing it from the bloodstream.

Previous studies have shown that both low-carb diets and the Mediterranean diet reduce after-meal elevations in blood sugar, which likely lowers levels of triglycerides and LDL cholesterol.

How Was the Study Done?

The goal was to compare effects of three diets in overweight type 2 diabetics in Israel over the course of one year.  Study participants totalled 259.  Average age was 56, average weight 86 kg (189 lb), average hemoglobin A1c 8.3%, and average fasting plasma glucose (sugar) was 10.3 mmol/L (185 mg/dl).  [Many diabetics in the U.S. fit this profile.]  People taking insulin were excluded from the study, as were those with proliferative diabetic retinopathy—no reasons given. 

Participants were randomly assigned to one of three diets, so there were about 85 in each group.  [Over the course of one year, people dropped out of the study for various reasons, leaving each group with about 60 subjects.] 

Here are the diets:

  • 2003 ADA (American Diabetes Association) diet:  50-55% of total caloric intake from carbohydrate (mixed glycemic index carbs), 30%  from fat, 20% from protein
  • Traditional Mediterranean (TM):  50-55% low-glycemic-index carbs, 30% fat—high in monounsaturated fat, 15-20% protein
  • Low-carb Mediterranean (LCM) :  35% low-glycemic-index carbs, 45% fat—high in monounsaturated fat, 15-20% protein

Patients were followed-up by the same dietitian every two weeks for one year.  All were advised to do aerobic exercise for 30-45 minutes at least three days a week.

Olive oil is traditionally the predominant form of fat in the Mediterranean diet and is a particularly rich source of monounsaturated fat.  At no point in this report was olive oil mentioned, nor any other source of monounsaturated fat.  Until I hear otherwise, I will assume that olive oil was the major source of monounsaturated fat in the TM and LCM diets. 

 All diets were designed to provide 20 calories per kilogram of body weight. 

In all three diets, saturated fat provided 7% of total calories.  Monounsaturated fatty acids provided 23% of total calories in the LCM, and  10% in the other two diets.  Polyunsaturated fatty acids provided 15% of calories in the LCM, and 12% in the other two diets.  The ADA diet provided 15 grams of fiber, the TM had 30 g, and the LCM had 45 g.

Adherence to the assigned diet was assessed with a “food frequency questionnaire” administered at six months.

What Did the Researchers Find?

Average reported energy intake was similar in all three groups: 2,222 calories per day.

Monounsaturated fat intake differences were statistically significant: 14.6, 12.8, and 12.6% for the LCM, TM, and ADA diets, respectively.  Polyunsaturated fat intake differences were statistically significant: 12.9, 11.5, and 11.2% for the LCM, TM, and ADA diets, respectively.

Percentage of energy from carbs was highest for the ADA diet (45.4%), intermediate for the TM diet (45.2%), and lowest for the LCM diet (41.9%).

At the end of 12 months, all three groups lost about the same amount of weight (8-9 kg or 18-20 lb), body mass index, and waist circumference.

Hemoglobin A1c fell in all three groups, but was significantly greater for the LCM group than for the ADA diet (6.3% absolute value vs 6.7%).

Triglycerides fell in all three groups, but was significantly greater for the LCM diet compared to the ADA diet.

The LCM group achieved a significant increase (12%) in HDL cholesterol compared to the ADA diet, but not different from the TM group.

LDL cholesterol fell in all three groups, and the LCM group’s drop (25%) was clearly superior to that of the ADA diet (14%) but about the same as the TM diet (21%).

Conclusions of the Investigators

We found that an intensive community-based dietary intervention reduced cardiovascular risk factors in overweight patients with [type 2 diabetes] for all three diets.  The LCM group had improved cardiovascular risk factors compared to either the ADA or the TM groups.

Only the LCM improved HDL levels and was superior to both the ADA and TM in improving glycaemic control.

It would appear that the low carbohydrate Mediterranean diet should be recommended for overweight diabetic patients.

My Comments

There’s no way the average diabetic could replicate this low-carb Mediterranean diet without working closely with a dietitian or nutritionist.

Any superiority of this low-carb Mediterranean diet may have as much to do with the increased monounsaturated fat intake as with the reduced carb consumption.  Monounsaturated fatty acid consumption is thought to improve insulin sensitivity. 

NutritionData’s Nutrient Search Tool can give you a list of foods high in monounsaturated fat.

The Mediterranean diet and low-carb diets independently have been shown to lower after-meal glucose levels, which probably lowers LDL cholesterol and triglycerides.

I’m disappointed the dietitians were not able to achieve a lower level of carbohydrate consumption in the low-carb Mediterranean diet group.  I suspect if they had, improvements in glucose control and lipids would have been even better.  But proof awaits another day.

We saw last year an article in the Annals of Internal Medicine that showed a dramatic reduction in the need for glucose-lowering drugs in type 2 diabetics following a different low-carb Mediterranean diet over four years, compared to a low-fat American Heart Association diet.  These two studies convince me a low-carb Mediterranean diet has real life-preserving and life-enhancing potential. 

Diabetics looking for a low-carb Mediterranean diet today have several options:

If you’re aware of any other low-carb, explicitly Mediterranean-style diets, please share in the Comments section.

Steve Parker, M.D. 

References: 

Elhayany, A., Lustman, A., Abel, R., Attal-Singer, J., and Vinker, S.  A low carbohydrate Mediterranean diet improves cardiovascular risk factors and diabetes control among overweight patients with type 2 dabetes mellitus:  a 1-year prospective randomized intervention study.  Diabetes, Obesity and Metabolism, 12 (2010): 204-209.

Esposito, Katherine, et al.  Effects of a Mediterranean-style diet on the need for antihyperglycemic drug therapy in patients with newly diagnosed type 2 diabetes.  Annals of Internal Medicine, 151 (2009): 306-314.

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March 7, 2010 · 2:58 PM

Book Review: The New Atkins for a New You

Here’s my review of The New Atkins for  a New You, a weight-loss book by Dr. Eric Westman, Dr. Stephen Phinney, and Dr. Jeff Volek released a week ago.  The copyright holder is Atkins Nutritionals, Inc.  Under Amazon.com’s five-star rating system, I give it four stars (“I like it”).  

♦   ♦   ♦ 

The most exciting nutritional medicine development in recent memory is the fact that saturated fat consumption is not a significant cause of heart disease and premature death. The same goes for for total fat and cholesterol.  When enough physicians, nutritionists, and dietitians learn this, low-carb eating will take off like a rocket.

For those unfamiliar with the Atkins diet, it is designed for weight loss via high fat consumption and major carbohydrate restriction.  Protein intake is a bit higher than average.  As long as carbohydrates (carbs) are kept low, other foods are mostly unlimited.  Atkins has four phases.  As you graduate from one phase tothe next, more carbs are allowed, adding some carb sources before others (the Carb Ladder). 

Atkins has been around for years.  It’s not just a weight-loss diet; it’s a lifetime way of eating.

Doctors Westman, Phinney, and Volek are leaders in low-carb nutritional science.  The last time Atkins peaked (2003), we didn’t have the scientific studies backing up safety of the diet.  Now we do, in large part thanks to these guys. 

Physicians see beaucoup patients with overweight-related medical conditions.  We’re not going to recommend a diet that causes heart attacks, strokes, and other major medical complications.  Published research over the last eight years has established the relative safety of very low-carb diets, particularly Atkins.  Low-carb diets may even be healthier than the low-fat, high-carb diet that has been recommended by U.S. public health authorities for the last forty years.  Come to think of it, our current obesity and diabetes epidemics started around that same time.

The book covers nutrition basics, day-to-day practical application of Atkins eating, recipes and detailed meal plans, and the science behind the program.    

What’s New Since Dr. Atkins’ 2002 Book?

  • adaptations for vegetarians and vegans
  • adaptations for Latinos
  • coffee is now OK
  • introduction of the term “foundation vegetables” and almost doubling the amount of vegetables allowed in Phase 1: “approximately six cups of salad and up to two cups of cooked vegetables, depending upon the ones you select”
  • more flexility, such as the option to skip Phase 1 (induction)
  • focus on adequate protein intake, based on your height
  • emphasis on getting enough omega-3 fatty acids
  • no emphasis on supplements and low-carb products sold by Atkins Nutritionals,Inc.
  • diet journals—a personal record of your weight-loss journey—are recommended
  • eliminate or minimize “induction flu” and constipation (in Phase 1) by eating at least 1/2 teaspoon of salt daily [I’m skeptical.]
  • discussion of the trendy omega-6/omega-3 fatty acid ratio
  • favor monounsaturated fatty acids (e.g., olive oil, canola oil) over certain polyunsaturated fats, as in oils from corn, soybeans, sunflower, cottonseed, and peanuts
  • no mention of testing urine for ketosis
  • more discussion of psychological aspects of weight

The lack of ads for Atkins Nutritionals products is welcome and refreshing.  Too many of the official Atkins books read like infomercials, which diminishes credibility.

A vegetarian or vegan “Atkins diet” is just not something I can visualize.

What Could Have Been Done Better?

  • no specific amounts given for these recommended supplements: calcium, vitamin D, omega-3 fats, multivitamin, magnesium and other minerals (except “no iron”).  [Is the idea to encourage a visit the official Atkins website?]
  • little guidance for physicians who are to advise diabetics doing Atkins.  Few physicians are familiar enough with the program to make the necessary changes in particular diabetic medications.
  • little discussion of the constipation and leg cramps that often accompany very low-carb diets
  • the hype on the cover: “How would you like to LOSE UP TO 15 POUNDS IN TWO WEEKS!”  [To their credit, the authors note that such results are not typical.]
  • nearly all the measurements are U.S. Customary.  Metric users are out of luck.
  • four phases seem a bit much.  The beauty of Atkins Phase 1 is its simplicity. 

My favorite sentence: “White flour is better suited to glue for kindergarten art projects than to nutrition.”

My least favorite sentence: “We can’t stress strongly enough that the best diet for you is one composed of foods you love.”  I love apple pie and Cinnabon cinnamon rolls, but they won’t help me manage my weight.

The only error I found worth mentioning is minor.  The authors state that the American Heart Association recommends consumption of fish three times a week. The official policy is still “at least twice weekly.”

The book is very practical and easily understood by average people.  Most will skip the science chapters at the end.  I know the basic Atkins program works at least short-term; many of my patients have done it.

In summary, the book has nearly everything you need to be successful with the Atkins diet. 

As far as I know, there are no comprehensive long-term studies (e.g., 10+ years) regarding health outcomes of Atkins-style eating.  In other words, does Atkins have any effect on longevity, cancer, heart attacks, strokes, etc.?  But very few of the popular diets have these data either.  The best researched ways of eating in this respect are the Mediterranean diet and vegetarian diets.

Steve Parker, M.D.

Disclosure:  I was given nothing of value for this review by the authors, publisher, or Atkins Nutritionals, Inc.  I wrote it for the benefit of my patients and readers.

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December 1, 2009 · 2:00 AM

Book Review: Atkins Diabetes Revolution

I must give credit to Dr. Robert C. Atkins for popularizing an approach – carbohydrate restriction – that helps people with diabetes control their disease, and likely helps prevent type 2 diabetes in others.  Mary C. Vernon and Jacqueline Eberstein do a great job explaining his program in their 2004 book, Atkins Diabetes Revolution: The Groundbreaking Approach to Preventing and Controlling Type 2 Diabetes. 

On the Amazon.com five-star rating scale, I give this book four stars.

I can best summarize this book by noting that it is the standard Atkins diet with a few modifications: 1) special supplements  2) you add additional carbs to your diet more slowly  3) the warning that diabetics may well end up with a lower acceptable lifetime carbohydrate intake level.

By way of review, the Atkins diet is a very low-carb diet, particularly in the two-week induction phase.  “Very low-carb” means lots of meat, chicken, fish, eggs, limited cheese, and 2-3 cups daily of salad greens and low-carb veggies like onions, tomatoes, broccoli, and snow peas.  After induction phase, you slowly add back carbs on a weekly basis until weight loss stalls, then you cut back on carbs.

As an adult medicine specialist, I have no expertise in pediatrics.  I didn’t read the two chapters related to children.

The authors present “complimentary medicine”in a favorable light.  Unsuspecting readers need to know that much of complementary medicine is based on hearsay and anecdote, not science-based evidence.  In that same vein, the two chapters on supplements for diabetes and heart disease recommend a cocktail of supplements that I’m not convinced are needed.  I don’t know a single endocrinologist or cardiologist prescribing these concoctions.  Then again, I could be wrong.   

Vernon and Eberstein provide two excellent chapters on exercise.

A month of meal plans and recipes are provided for 20, 40, and 60-gram carbohydrate levels.  [The average American is eating 250-300 g of carbs daily.]  The recipes look quick and easy, but I didn’t prepare or taste any of them.

The 5-hour glucose and insulin tolerance test (GTT, paged 61) that Dr. Atkins reportedly ran on all patients who came to him is rarely done in other medical clinics.  This doesn’t mean it’s wrong, but certainly out of the mainstream.  The authors admit that at least a few people will have to count calories – specifically, limit total calories – if the basic program doesn’t control diabetes, prediabetes, and the metabolic syndrome.  Limiting portion size will speed weight loss, they write.

What we don’t know with certainty is, will long-term Atkins aficionados miss out on the health benefits of higher consumption of fruits, vegetables, legumes, and whole grains?  Much of the scientific literature suggests, “Yes.”

What if we compare the long-term outlooks of a diabetic Atkins follower with a poorly controlled diabetic who’s 80 pounds overweight and eating a standard American diet?  The Atkins follower is quite likely to be healthier  and live longer.

Steve Parker, M.D.

 

 

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November 24, 2009 · 2:00 AM

Are Vegetarian Diets Any Good For Diabetes?

Plant-based diets may offer special benefits to people with diabetes, according to a recent review article by U.S. researchers who reviewed the pertinent English language literature published since 1966.  They found 116 potentially relevant articles, 10 of which were directly related to diabetes management and glucose control.

The authors failed to define “vegetarian” early on.  Some vegetarians eat eggs, some eat cheese, some drink milk.  I assume vegans eat no animal products whatsoever.  On the last page of the review the authors write that a vegetarian “does not eat meat, fish, or poultry” although it’s not clear if that applies throughout the review.  There are many references to “low-fat vegetarian” diets, with little or no mention of moderate- or high-fat vegetarian diets.

The authors often refer to vegetarian diets as “plant-based.”  No doubt, they are.  But even the healthy Mediterranean diet is considered plant-based, while clearly not vegetarian.

It’s also unclear whether they focused on type 1 or type 2 diabetes.  My sense is, probably type 2.

Here are the major points: 

  1. Are vegetarians less likely to develop diabetes?  Observational studies have found a lower prevalence of diabetes among vegetarians compared to non-vegetarians, especially among Seventh Day Adventists.  In other studies, meat consumption is linked to higher risk of diabetes among women. 
  2. Do vegetarian diets help control diabetes?  Several small studies showed that low-fat near-vegetarian and vegan diets improved glucose control and insulin sensitivity and reduced diabetes medication use, compared with a traditional diabetes diet – which is typically low-fat and high-carb.  I’m not sure, but I assume that the intervention diets were not heavy in refined, processed carbohydrates, but instead consisted of natural whole plant foods.  “Weight loss accounts for much although not all, of the effect of plant-based diets on glycemic control,” they write.
  3. Heart disease is quite common in older diabetics.  Do vegetarian diets offer any cardiac benefits?  They cite Dr. Ornish’s Lifestyle Heart Trial of a low-fat vegetarian diet and intensive lifestyle intervention: smoking cessation, stress management (meditation?), mild exercise, and group meetings.  Dr. Ornish’s program reduced LDL cholesterol by 37%, reversed heart artery blockages in 82% of participants, and found 60% lower risk of cardiac events compared to the control group. Dr. Ornish’s Multisite Lifestyle Cardiac Intervention Program also documented impressive cardiac results at 12 weeks, but had no control group.  Dr. Caldwell Esselstyne is also mentioned in this context.
  4. Vegetarian diets are linked to lower blood pressure, which may help prolong life and prevent heart attacks and strokes.
  5. Antioxidant-rich foods like fruits and vegetables—common in the Mediterranean diet and vegetarian diets—may lower cardiovascular disease risk. 
  6. People with diabetes are at risk for impaired kidney funtion.  In women with impaired baseline kidney funtion, high animal protein intake is associated with continued kidney deterioration. 
  7. A small study showed dramatic improvement in type 2 diabetics with painful neuropathy over 25 days on a low-fat vegan diet and a daily 30-minute walk.  Many participants were able to reduce diabetes drug dosages.
  8. Do any diabetes advocacy associations endorse vegetarian diets for people with diabetes?  The American Dietetic Association deems that vegetarian and vegan diets, if well-planned, are nutritionally adequate. I don’t know the position of the American Diabetes Association.  Vegetarians need planning to get adequate vitamin D, B12, and calcium.
  9. “Low-fat vegetarian and vegan diets do not require individuals to limit energy or carbohydrate intake….”  If true (and these guys should know), that might broaden the diet’s appeal.
  10. I saw no mention of decreased overall mortality in vegetarians.

My Comments

Have you heard of the Physicians Committee for Responsible Medicine?  Their president is Neal Barnard, the lead author of the study at hand.  He has a new book on reversal of diabetes with a low-fat vegetarian diet.

The authors cite a journal article (reference #16) in support of plant-based diets, but the article doesn’t mention a vegetarian or vegan diet—it’s high-carb, high-fiber diet.  I didn’t review all 92 of their references to see if any others were misleading.

“Plant-based diets” must be a euphemism for vegetarian diets.  Too many people shut down when you talk to them about vegetarian diets.

I won’t rule out the possibility that vegetarian/vegan diets may be helpful in management of diabetes.  Such diets are, of course, 180 degrees different from the very low-carb diets I’ve reviewed favorably in these pages!  Both models, ideally, move away from the over-processed, concentrated carbohydrates so prevalent in Western culture.  Perhaps that’s the unifying healthy theme, if there is one. 

Or different sub-types of diabetes respond better to particular diets.

I heartily agree with the authors that larger clinical trials of vegetarian diets in diabetics are needed.  I’d love to see a long-term randomized controlled trial comparing a very low-carb diet diet with a low-fat vegetarian diet.  That’s the best way to settle which is better for diabetics: vegetarian or low-carb.

It’ll never be done.

Has a vegetarian diet helped control your diabetes?

Steve Parker, M.D.

Reference:  Barnard, Neal, et al.  Vegetarian and vegan diets in type 2 diabetes management.  Nutrition Reviews, 67(2009): 255-263.   doi: 10.1111/j.1753-4887.2009.00198.x

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November 22, 2009 · 2:00 AM

Low-Carb Ketogenic Diet for Overweight Diabetic Men: A Pilot Study

A low-carb ketogenic diet in patients with type 2 diabetes was so effective that diabetes medications were reduced or discontinued in most patients, according to U.S. researchers.  The 2005 report recommends that similar dieters be under close medical supervision or capable of adjusting their own medication, because the diet lowers blood sugar  dramatically. 

Methodology

Twenty-eight overweight people with type 2 diabetes were placed on the study diet and followed for 16 weeks.  Seven people dropped out, so the analysis involved 21, of which 20 were men—the study was done at a Veterans Administration clinic.  Thirteen were caucasian, eight were black.  Average age was 56; average body mass index was 42.  The seven dropouts were unable to come to the scheduled meetings or couldn’t follow the diet.  No dropout complained of adverse effects of the diet.

Results

Participants were instructed on the Atkins Induction Phase diet, which daily includes:

  • under 20 g carbohydrate
  • one cup of low-carb vegetables
  • two cups of salad greens
  • four ounces of hard cheese
  • unlimited meat, poultry, fish, eggs, shellfish
  • a multivitamin

At the outset, diabetes medication dosages were reduced in this general fashion: insulin was halved, sulfonyureas were halved or discontinued.  If the participant were taking a diuretic (fluid pill), low doses were discontinued; high doses were halved.

Study subjects returned every two weeks for diet counseling and medication adjustment (based on twice daily glucose readings and episodes of hypoglycemia).  Food cravings and/or good progress on weight goals triggered a 5-gram (per day) weekly increase in carbohydrate allowance.  In other words, if a participant’s weight loss goal was 20 pounds and he’d already lost 10, he could increase his daily carbs during the next week from 20 to 25 g.  Carbs could be increased weekly by five gram increments as long as weight loss progressed.  [This is typical Atkins.]   Food records were analyzed periodically.   

Results

  • hemoglobin A1c decreased from an average baseline of 7.5% down to 6.3% (a 1.2% absolute decrease and 16% relative drop)
  • the absolute hemoglobin A1c decrease was at least 1.0% in half of the participants
  • diabetic drugs were reduced in 10 patients, discontinued in seven, and unchanged in four
  • average body weight decreased by 6.6%, from 131 kg (288 lb) to 122 kg (268 lb)
  • triglycerides decreased 42%, while cholesterols (total, HDL, and LDL) didn’t change significantly
  • no change in blood pressures
  • average fasting glucose decreased by 17% (by week 16)
  • uric acid decreased by 10%
  • no serious adverse effects occurred
  • one hypoglycemic event involved EMS but was treated without transport
  • only 27 of 151 urine ketone measurements  were greater than trace

My Comments

The degree of improvement in hemoglobin A1c—our primary gauge of diabetes control—is equivalent to that seen with many diabetic medications.  I see many overweight diabetics on two or three drugs and a standard “diabetic diet,” and they’re still poorly controlled.  This diet could replace the expense and potential adverse effects of an additional drug.   

In August this year I blogged about a study comparing the Atkins diet with a traditional low-fat diet in overweight diabetic black women in the U.S.  As measured at three months, the Atkins diet proved superior for weight loss and glucose control.

This study at hand is small, but certainly points to the effectiveness of an Atkins-style very low-carb ketogenic diet in overweight men with type 2 diabetes.

Steve Parker, M.D.

Yancy, William, et al.  A low-carbohydrate, ketogenic diet to treat type 2 diabetes [in men].  Nutrition and Metabolism, 2:34 (2005).   doi: 10.1186/1743-7075-2-34

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November 19, 2009 · 12:29 AM

Book Review: 21 Life Lessons From Livin’ La Vida Low-Carb

Here’s my review of Jimmy Moore’s new book, 21 Life Lessons From Livin’ La Vida Low-Carb: How the Healthy Low-Carb Lifestyle Changed Everything I Thought I Knew.  I rate it five stars, Amazon.com’s highest rating.

♦   ♦   ♦

Thinking about quitting your low-carb lifestyle?  Read this book first.

Jimmy Moore is a leading advocate for low-carb eating.  His purpose with this book is to educate, encourage, and inspire overweight people to begin or maintain their own low-carb journey.  And he succeeds in spades.

Mr. Moore assumes the reader already knows how to do low-carb eating.  If you don’t, I’m sure Mr. Moore would recommend Dr. Atkins New Diet Revolution as the single best source.  As with all diets, low-carb eating has a high drop-out rate.  Most people lose some weight then return to their old way of eating, gaining the weight back.

Even as the author of a balanced, calorie-restricted diet book, I’ll admit that many people have had phenomenal success with low-carb diets, without caloric restriction.  Mr. Moore is one of those: 180 pounds (82 kg) weight loss in one year, and sustained over five years.  Could he be lying?  Sure.  But my gut feeling is he’s not. 

This book is not only a survey of the low-carb world covering the last decade, its an autobiography.  He shares his traumatic upbringing and the frustrating premature death of his morbidly obese brother from heart disease.  You’ll learn about Mr. Moore’s movie career alongside George Clooney.  I was also surprised to learn that Mr. Moore lost 170 pounds (77 kg) in 1999, not on a low-carb diet, but a low-fat one!  Then what happened?  I won’t spoil it for you.  Mr. Moore also owns up to his regrettable and embarrassing affiliation with the Kimkins diet in 2007.

The only weak chapter is the one on childhood obesity.  Mr. Moore moves away from his previous science- and evidence-based arguments, using personal opinion and anecdote more often.  This partly reflects the fact that childhood obesity hasn’t been studied nearly as much as the adult version.

I particularly like Mr. Moore’s review of the scientific evidence in favor of low-carb eating.  The science was inspired and driven by the low-carb craze of 1998-2004.  But the study results weren’t published until after the fad peaked.  So most people aren’t familiar with the science.  Mr. Moore presents it in very understandable terms, which is a gift.

As heavily invested as he is in low-carb eating, does Mr. Moore condemn other methods of weight management?  By no means.  He repeatedly writes: “The point is to find the proven nutritional plan that works for you, follow that plan as exactly as prescribed by the author, and then stick to it for the rest of your life.” 

Steve Parker, M.D.

Additional information: Jimmy Moore’s Livin’ La Vida Low-Carb Blog

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September 17, 2009 · 12:20 PM

Low-Carb Diet Lowers Glucose Levels More Than Standard-Carb Diet

Stephan Guyenet, Ph.D., (neurobiology) posted a graph at his blog (Whole Health Source) showing dramatically better glucose levels in people with diabetes eating a low-carb diet (20% of energy from carbs) compared to those on a 55% carb diet. 

No great surprise, but it has more impact when you see it graphed out.

Steve Parker, M.D.

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