Tag Archives: low-carb

September 1, 2009 · 6:01 PM

My Ketogenic Mediterranean Diet: Day 1

 

Very low-carb chicken

Very low-carb chicken

Today I’m starting a very low-carb diet, the Ketogenic Mediterranean Diet, to lose only about 10 lb (4.55 kg) of fat I’ve accumulated around my waist over the last six months. 

 

I gained the weight intentionally, so I’d have something to experiment on.  Cookies, candy bars, ice cream, cinnamon rolls and other pastries, pies, cakes, fried pies, french fries, shakes and malts—all these reliably put extra weight on me.  It’s not been a burden to gain the weight.  I did it for Science!

My current stats

Weight: 170 lb (77.3 kg)

Height: 71 inches (180 cm)

Body mass index: 23.8

Waist circumference: 36.5 inches (92.7 cm)

Usual  caloric intake: 2400/day (from prior self-experimentation and food diaries)

Activity level:  somewhat active

Health status:  Good.  No trouble with high cholesterol or trigylcerides, diabetes, heart disease, high blood pressure.

Comments

My body mass index is in the healthy range, so the 10 pounds I want to lose are “vanity pounds.”  You wouldn’t call me fat.  Maybe “a little chubby.”  My daughter and mother both spontaneously mentioned the excess weight to me.  My usual adult weight is around 160 pounds.  I dropped to 148 once through caloric restriction; my wife thought that was too low. 

My Plans

I’ll report here daily regarding weight, dietary transgressions, exercise, random thoughts, etc.  If it’s not too much hassle, I’ll track my food intake at NutritionData.com and share the nutritional analysis weekly.  I’m hoping I don’t get too busy to keep this up.

Steve Parker, M.D.

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August 15, 2009 · 10:33 AM

Atkins Diet Beats Low-Fat Diet Over Three Months in Overweight Diabetic Black Women

MPj04384250000[1]A recent study compared effects of a low-carb versus low-fat diet in overweight diabetics (mostly blacks).  After one year, the only major difference they found was  lower HDL cholesterol in the low-carb eaters.  The low-carb diet was more effective measured at three months into the study.  Study participants were overwhelmingly black women, so the findings may not apply to you.

Background

The authors note at the outset that:

Optimal weight loss strategies in patients with type 2 diabetes continue to be debated, and the best dietary strategy to achieve both weight loss and glycemic control . . . is unclear.

They also note that in short-term randomized studies, low-carb diets help improve glucose control in type 2 diabetics.

Methodology

Participants (105) were randomized to either:

  • a low-fat diet in the fashion of the Diabetes Prevention Program, with a fat gram goal of 25% of energy needs, or . . .
  • the Atkins diet, including the 2-week induction phase and gradually increasing carb grams weekly, etc.

The adult partipants were black (64%), Hispanic (16%), white (15%), or other.  Women were 80% of the group.  Average age 54.  Average weight 215 pounds (98 kg).  Average BMI 36.  Most of them were taking metformin, half were taking a sulfonylurea, 30% were on insulin.  Thiazolidinedione drugs were discontinued since they cause weight gain as a side effect.  Short-acting insulins were changed to glargine (Lantus) to help avoid hypoglycemia.  For the low-carb group initially, insulin dosages  were reduce by half and sulfonylureas were stopped (again, to minimize hypoglycemia).  For the low-fat group, insulin was reduced by 25% and sulfonylurea by 50%.  Metformin was not adjusted.  Subjects were instructed to keep daily food diaries.  Goal rate of weight loss was one pound per week.   

Results

The drop-out rate by the end of 12 months was the same in both groups – 20%.  The low-carbers lost weight faster (3.7 lb/month) in the first three months, but by month twelve each group had the same 3.4% reduction of weight (6.8 lb or 3 kg).  As measured at 3 months, low-carbers were down 11.4 lb (5.2 kg) and low-fat dieters were down 7 lb (3.2 kg).  Maximum weight loss was at 3 months, then they started gaining it back.  At 12 months, low-carb subjects using insulin were on 10 less units, while low-fat dieters were using 4 more units (not statistically significant).  Hemoglobin A1c measured at 3 months was down 0.64 in the low-carb group and down0.26 in the low-fat.  By 12 months, HgbA1c’s were back up to baseline levels for both groups.  Blood lipids were the same for both groups at 12 months except HDL was about 12% higher in the low-carb dieters.

At baseline, subjects derived 43% of calories from carbohydrates, 36% from fats, 23% from proteins.  At three months, the low-carb group ate 24% of calories as carbohydrates (estimated at 77 grams of carb daily) and 49% from fat.  The low-fat group at 3 months derived 53% of calories from carbohydrate (199 grams/day) and 25% from fat. Diet compliance deteriorated as time passed thereafter. 

Study Author Conclusions

After one year, the low-carb and low-fat groups had similar weight reductions.  The low-carb dieters raised their HDL cholesterol levels significantly [which may protect against heart disease].

My Comments

Lasting weight loss is difficult!  Down only 6.8 pounds for a year of  effort. 

These study participants needed to lose a lot more than 6.8 pounds.  They needed to lose 50.  Both groups were woefully noncompliant with diet recommendations by the end of the study year.  They were eating more carbs or other calories than they were assigned.  But their results weren’t much different than other groups studied for an entire year. 

How do we keep people fired up about maintaining their weight-loss efforts?  The solution to that problem will win someone a Nobel Prize.

The Atkins diet was superior – for weight loss and glycemic control – when measured at three months, when compliance by both groups was still probably fairly good.

Results of this study may apply only to black women.  There weren’t enough men and other ethnic groups to make meaningful comparisons.    

Steve Parker, M.D.        

Reference:  Davis, Nichola, et al.  Comparative study of the effects of a 1-year dietary intervention of a low-carbohydrate diet versus a low-fat diet on weight and glycemic control in type 2 diabetes.  Diabetes Care, 32 (2009): 1,147-1,152.

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July 10, 2009 · 4:11 AM

Low-Glycemic-Index Eating Had No Effect on Control of Mild Type 2 Diabetes

Caprese salad

Caprese salad

A Canadian study last year found no overall effect on type 2 diabetes control by using a low-glycemic-index diet and lower-carbohydrate diet, although the low-glycemic-index diet did reduce post-meal glucose levels and C-reactive protein.

Background

For many years, a high-fat, low-carbohydrate diet was recommended for type 2 diabetics.  Then in 1979 the American Diabetes Association recommended a high-carb, low-fat diet.  Later, the ADA allowed more fat, mostly monounsaturated. 

The experts are still debating how much and what kind of carbohydrate people with diabetes should eat.  Recent years have seen a trend towards lower carbohydrate intake and lower-glycemic-index eating.  Much of the supportive evidence we have is based on short-term studies – six to 12 weeks. 

A Cochrane review in 2004 concluded that there was no high-quality data on the effectiveness of dietary treatment of diabetes.

The authors of the Canadian study at hand wrote:

Although almost everyone would agree that diet is the cornerstone of diabetes therapy, there is marked disagreement about what kind of dietary advice is best, particularly with respect to dietary carbohydrate.

We can put a man on the moon, but still aren’t sure what’s the best diet for people with diabetes despite years of experience and experimentation.

The Canadian researchers aimed to compare the effects of altered glycemic index and amount of carbohydrate on hemoglobin A1c, blood glucose, lipids, and C-reactive protein in men and women with type 2 diabetes.

Methodology

162 subjects with mild diabetes, 35-75 years old, managed by diet alone, were randomly assigned to one of three diet groups:

  1. high-carb, high-glycemic-index (“high-GI“): 47% of calories from carb, 31% of cals from fat, glycemic index 63
  2. high-carb, low-glycemic-index (“low-GI“): 52% of cals from carb, 27% of cals from fat, glycemic index 55
  3. low-carb, high-monounsaturated fat (“low-CHO“): 39% of cals from carb, 40% of cals from fat, glycemic index 59

Average body mass index was 31 (mildly obese); average weight 83 kg (183 lb).  The study lasted one year, a major strength of the study.

Results One Year Later

Hemoglobin A1c rose from 6.1% to 6.3%, with no difference between the various diet groups.  There were no differences in insulin levels, whether fasting or two hours after an oral glucose tolerance test.  Blood sugar levels after a glucose tolerance test were 7% lower with the low-GI diet compared to the other diet groups.  No difference in LDL cholesterol levels.  Little effect on triglycerides and HDL cholesterol.  No differences in weight.  C-reactive protein in the high-GI group fell from3.34 mg/L to 2.75.  C-reactive protein in the low-GI group fell from 2.64 to 1.95.  [All these C-reactive protein readings are in the normal range.]        

Comments

Nearly all the people with diabetes I encounter are very different from this study cohort: they are on drug therapy for diabetes.  So the results here don’t  necessarily apply to the more typical cases of moderate or severe diabetes that require one or more glucose-control drugs. 

Low-carb diet advocates can justifiably argue that the carb intake was still too high, and that’s why their numbers weren’t better.  Vernon and Eberstein in their book, Atkins Diabetes Revolution, note that many people with type 2 diabetes will have to limit carboydrates (“net carbs”) to 40-60 grams a day.  In the study at hand, the low-carb diet aimed for 39% of calories from carbohydrates.  On a 2000-calorie diet, that’s 195 grams – a far cry from 60 grams.      

Low-Gi advocates also can justifiably argue that the glycemic index was not low enough to make a difference.  The researchers admit that the test diet reductions in carb intake and glycemic index were “modest.”  Perhaps they thought that more drastic reductions were unsustainable.

Attempts to control diabetes with low-carb or low-glycemic-index eating should make more dramatic changes.

The low-glycemic-index diet lowered two-hour glucose levels on the glucose tolerance tests.  The authors state that this parameter is a better indicator of heart disease risk – lower in this case – than are fasting glucose levels.  Findings suggests improvements in insulin resistance and/or pancreas beta cell function.  This finding may have no real-world clinical significance: remember that hemoglobin A1c levels were the same across all groups. 

The changes in C-reactive protein just don’t seem clinically significant to me (nor to an editorialist in the same journal issue).

The aforementioned editorialist, Dr. Xavier Pi-Sunyer, had an interesting comment:

This finding suggests that we must be careful about disrupting subjects’ or patients’ diets with radical , doctrinaire changes that may actually be counterproductive.  Furthermore, the diets had carbohydrate contents that varied from 39% to 52% of energy intake, and yet this variability had no effect on the subjects’ HbA1c.  This finding confirms previous reports that the proportion of carbohydrate in the diet is not very important in determining the concentration of fasting blood glucose and that variations of 10% to 15% of total calories make little difference to overall control in patients with early type 2 diabetes.

I would emphasize “. . . in patients with early type 2 diabetes.”

A Mediterranean-style diet, then, could be just as effective as, if not better than, all the other “diabetic diets” out there.

Steve Parker, M.D.

References:  Wolever, Thomas, et al.  The Canadian Trial of Carbohydrates in Diabetes (CCD), a 1-y controlled trial of low-glycemic-index dietary carbohydrate in type 2 diabetes: no effect on glycated hemoglobin but reduction in C-reactive protein.  American Journal of Clinical Nutrition, 87 (2008); 114-125.

Additional Resource:  Michael R. Eades, M.D.  Making worthless data confess.  The Blog of Michael R. Eades, December 13, 2008.  Accessed July 10, 2009.  [Highly critical analysis from a leading low-carb, high-protein advocate.]

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June 24, 2009 · 2:00 AM

High Protein Ketogenic Diet Beats High Protein/Medium Carb Diet in Men, at Least Short-Term

Low-Carb Steak

Low-Carb Steak

Scottish researchers last year reported greater weight loss and less hunger in obese men on a high-protein ketogenic diet compared to a high-protein, moderate-carbohydrate diet.

Background

Dietary protein seems to be more satiating – able to satisfy hunger, that is – than carbohydrate and fat. 

The typical Western (especially American) diet derives about 55-60% of total calories from carbohydrates.  When carbohydrate intake is very low, under 20-30 grams per day for example, fat stores are utilized as a source of energy to replace carb calories, resulting in fat breakdown waste products called ketone bodies.  These are ketogenic diets.  In them, carbs are replaced usually by both extra fat and extra protein. 

Methodology

Each of 17 obese men, 20 to 65 years old, were placed on two separate diets for four weeks each time.  Average weight was 111 kg.  Average body mass index was 35.  This was a residential program, but the subjects were allowed to leave and go to work.

  • Diet 1:  high-protein, low-carbohydrate, ketogenic.  30%, 4%, and 66% of energy (calories) as protein, carbohydrate, and fat, respectively.
  • Diet 2:  high-protein, medium-carbohydrate, nonketogenic.  30%, 35%, and 35% of calories as protein, carb, and fat, respectively.

Actually 20 men signed up, but three dropped out for personal reasons after starting. 

They could eat as much as they wanted. 

Results

Subjects had no overall preference for either diet.  No differences in the diets for desire to eat, preoccupation with food, or fullness.  Weight loss was greater for the low-carb diet tahn with the medium-carb diet: 6.34 kg vs 4.35 (P < 0.001).  Subjects lost more weight on their first diet than on their second.  Fasting glucose and HOMA-IR (a test of insulin resistance) was lower than baseline for the low-carb diet but not the other.  Total and LDL cholesterol were tended to fall in response to both diets, but to a statistically significantly great degree only on the medium-carb diet.  When eating the low-carb diet, subjects ate 300 calories per day less than on the medium-carb diet.  [ketones were measures?]

Discussion

We have to assume that study subjects were of Scottish descent.  Applicability of these results to other ethnic groups is not assured.  Similarly, results don’t necessarily apply to women.

I’m surprised the medium-carb dieters, eating all they wanted, lost weight at all.  Must be a result of the high protein content or lower-than usual carbohydrate content of the study diet.  Study authors cite others who found that doubling protein intake from 15 to 30% of calories reduces food intake, which should lead to weight loss. 

Since protein content was the same on both diets, the greater weight loss seen on the low-carb ketogenic diet was the result of lower caloric intake, in turn due to less hunger.  The reduced energy intake could be due to lower carb or higher fat intake, or both.  The researchers cite one study finding no satiating effect of fat.  Some say that ketone bodies reduce appetite. 

Although the medium-carb diet showed greater improvements in total and LDL cholesterol, the low-carb diet changes trended in the “right” direction (down).

On the low-carb ketogenic diet, lower glucose levels and insulin resistance would tend to help people with (or prone to) type 2 diabetes, prediabetes, and some cases of metabolic syndrome. 

Steve Parker, M.D.

 References: 

Johnstone, Alexandra, et al.  Effects of a high-protein ketogenic diet on hunger, appetite, and weight loss in obese men feeding ad libitum.  American Journal of Clinical Nutrition, 87 (2008): 44-55.

Weigle, D.S., et al.  A high-protein diet induces sustained reductions in appetite, ad libitum caloric intake, and body weight despite compensatory changes in diurnal plasma leptin and ghrelin concentrations.  American Journal of Clinical Nutrition, 82 (2005): 41-48.

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June 20, 2009 · 2:00 AM

Low-Carb Diet Beats Low-Fat, Calorie-Restricted Diet

Body mass index 38

Body mass index 38

I found one of the early studies (2003) demonstrating the effectiveness and safety of an Atkins-style diet in the severely obese.  Doctors traditionally have been hesitant to recommend the Atkins diet out of concern for tolerability and potential increased atherosclerosis complication such as heart attacks, strokes, and poor circulation.

Methodology

The study enrolled 132 subjects with an average body mass index of 43, including 77 blacks and 23 women.  39% had diabetes, 43% had metabolic syndrome.  They were randomly assigned to either . . .

  1. a low-carb diet without caloric restriction (carbohydrates limited to 30 gm/day; vegetables and fruits with high ratios of fiber to carbohydrate were recommended), or
  2. a low-fat, calorie-restricted diet. 

Subjects followed their diets for six months.  The researchers never specified, but I’m assuming the diabetics were all type 2. 

Results

The drop-out rate was equally high in both groups: only 79 subjects completed the study.  The low-carb group lost 5.8 kg (13 lb); the low-fat group lost 1.9 kg (4 lb).  Analysis included the drop-outs, for reasons unclear to me.  White subjects lost more weight than blacks: 13 versus 5 kg (29 versus 11 lb).  Total cholesterol, HDL cholesterol, and LDL cholesterol levels did not change significantly within or between groups.  [HDL usually rises on a low-carb diet.]   Triglycerides fell 20% in the low-carb group and 4% in the other group.  For subjects with diabetes, glucose levels fell 26 mg/dl in the low-carb group compared to 5 mg/dl in the low-fat group.  Uric acid levels didn’t change in either group.  [Elevated uric acid levels can cause gout.]  No significant adverse reactions attibutable to the diets were recorded in either group.  Glycosylated hemoglobin fell from 7.8 to 7.2% in the low-carb group, with no change in the low-fat group.   

Take-Home Points  

It’s a small study, so results may not be very accurate or generalizable to other populations.

In this cohort with a high prevalence of diabetes, the low-carb diet was more effective than the low-fat/calorie-restricted diet for weight loss, with no adverse lipid changes to suggest increased long-term cardiovascular risk.  The low-carb diet helped control diabetes. 

Steve Parker, M.D. 

Reference:  Samaha, Frederick, et al.  A low-carbohydrate as compared with a low-fat diet in severe obesity.  New England Journal of Medicine, 348 (2003): 2,074-2,081.

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May 25, 2009 · 9:31 AM

Spanish Ketogenic Mediterranean Diet

Altea, Plaça de la EsglésiaEver heard of the Spanish Ketogenic Mediterranean Diet?  It looks like a low-carb quasi-Mediterranean diet.

Researchers with the University of Cordoba in Spain studied 40 subjects eating a low-carb “Mediterranean” diet for 12 weeks.  The results were strikingly positive.

Methodology

A medical weight loss clinic was the source of 40 overweight subjects, 22 males and 19 females, average age 38, average body mass index 36.5, average weight 108.6 kg (239 lb).  These folks were interested in losing weight, and were not paid to participate.

Nine subjects were not included in the final analysis due to poor compliance with the study protocol (3), the diet was too expensive (1), a traumatic car wreck (1), or were simply lost to follow-up (4).  So all the data are pooled from the 31 subjects who completed the study.

Blood from all subjects was drawn just before the study began and again after 12 weeks of the diet.

Study diet:  Low-carbohydrate, high in protein [and probably fat, too], unlimited in calories.  Olive oil was the main source of fat (at least 30 ml daily).  Maximum of 30 grams of carbohydrates daily as green vegetables and salad.  200-400 ml daily of red wine.  The authors write:

Participants were permitted 3 portions (200 g/portion) of vegetables daily: 2 portions of salad vegetables (such as alfalfa sprouts, lettuce, escarole, endive, mushrooms, radicchio, radishes, parsley, peppers, chicory, spinach, cucumber, chard and celery), and 1 portion of low-carbohydrate vegetables (such as broccoli, cauliflower, cabbage, artichoke, eggplant, squash, tomato and onion).  3 portions of salad vegetables were allowed only if the portion of low-carbohydrate vegetables were not consumed.  Salad dressing allowed were: garlic, olive oil, vinegar, lemon juice, salt, herbs and spices.

The minimum 30 ml of olive oil were distributed unless in 10 ml per principal meal (breakfast, lunch and dinner).  Red wine (200–400 ml a day) was distributed in 100–200 ml per lunch and dinner.  The protein block was divided in “fish block” and “no fish block”.  The “fish block” included all the types of fish except larger, longer-living predators (swordfish and shark).  The “no fish block” included meat, fowl, eggs, shellfish and cheese.  Both protein blocks were not mixed in the same day and were consumed individually during its day on the condition that at least 4 days of the week were for the “fish block”.

Trans fats (margarines and their derivatives) and processed meats with added sugar were not allowed.

Vitamin and mineral supplements were given.

Subjects measured their ketosis state every morning with urine ketone strips.

Results (averaged)

  • Body weight fell from 108.6 kg (239 lb) to 94.5 kg (209 lb), or 2.5 pounds per week
  • Body mass index fell from 36.5 to 31.8
  • Systolic blood pressure fell from126 to 109 mmHg
  • Diastolic blood pressure fell from 85 to 75 mmHg
  • Total cholesterol fell from 208 to 187 mg/dl
  • LDL chol fell from 115 to 106 mg/dl
  • HDL chol rose from 50 to 55 mg/dl
  • Fasting glucose dropped from 110 to 93 mg/dl
  • Triglycerides fell from 219 to 114 mg/dl
  • No significant differences in male and female subjects
  • No adverse reactions are mentioned

Researchers’ Conclusions

The SKMD [Spanish Ketogenic Mediterranean Diet] is safe, an effective way of losing weight, promoting non-atherogenic lipid profiles, lowering blood pressure and improving fasting blood glucose levels.  Future research should include a larger sample size, a longer term use and a comparison with other ketogenic diets.

My Comments

The researchers called this diet “Mediterranean” based on olive oil, red wine, fish, and vegetables.

What’s “Not Mediterranean” is the paucity of carbohydrates (including whole grains); lack of yogurt, nuts, and legumes; and the high meat/protein intake.

The emphasis on olive oil, red wine, and fish could make this healthier than other ketogenic diets.

Ketogenic diets are notorious for high drop-out rates compared to other diets.  Most people can follow a ketogenic diet for only two or three months.  But several studies suggest greater short-term weight loss for people who stick with it.  Efficacy and superiority are little different from other diets as measured at one year out.

Many of the metabolic improvements seen here might be duplicated with loss of 30 pounds (13.6 kg) over 12 weeks using any reasonable diet.

Average fasting blood sugars in these subjects was 109 mg/dl.  Although not mentioned by the authors, this is in the prediabetes range.  The diet reduced average fasting blood sugar to 93, which would mean resolution of prediabetes.  Dropping body mass index from 36 to 32 by any method would tend to cure prediabetes.

Elevated blood sugar is one component of the “metabolic syndrome.”  Metabolic syndrome was recently shown to be reversible with a Mediterranean diet supplemented with nuts.

I suspect this would be a good program for an overweight person with uncontrolled type 2 diabetes, too.  But it has never been studied in a diabetic population.  So, who knows for sure?

If you’re thinking about doing something like this, get more information and be sure to get your doctor’s approval first.

Steve Parker, M.D.

Addendum:

On April 6, 2008, I had a delightful conversation with Jimmy Moore, of Livin’ La Vida Low-Carb fame regarding this study.  It struck me that the Spanish Ketogenic Mediterranean Diet is probably higher in protein and lower in fat than many other ketogenic weight-loss diets.  Since fish is emphasized over other animal-derived foods, it’s likely also lower in saturated fat.  [In low-carb diets, carbohydrates are substituted with either fats or proteins.]  I’m also convinced I will eventually have to review the validity of the dogmatic diet-heart hypothesis:  Dietary saturated fat, total fat, and cholesterol contribute to atherosclerosis and associated premature death from heart attacks and strokes.

References and Additional Reading:

Perez-Guisado, J., Munoz-Serrano, A., and Alonso-Moraga, A.  Spanish Ketogenic Mediterranean diet: a healthy cardiovascular diet for weight loss.  Nutrition Journal, 2008, 7:30.   doi:10.1186/1475-2891-7-30

Bravata, D.M., et al.  Efficacy and safety of low-carbohydrate diets: a systematic review.  Journal of the American Medical Association, 289 (2003): 1,837-1,850.

Gardner, C.D., et al.  Comparison of the Atkins, Zone, Ornish, and LEARN diets for change in weight and related risk factors among overweight premenopausal women: the A TO Z Weight Loss Study: a randomized trial.  Journal of the American Medical Association, 297 (2007): 696-677.

Stern, L., et al.  The effects of low-carbohydrate versus conventional weight loss diets in severely obese adults: one-year follow-up of a randomized trial.  Annals of Internal Medicine, 140 (2004): 778-785.

Shai, Iris, et al.  Weight Loss with a Low-Carbohydrate, Mediterranean, or Low-Fat Diet.  New England Journal of Medicine, 359 (2008): 229-241.

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