Tag Archives: prediabetes

March 6, 2010 · 2:00 AM

My Ketogenic Mediterranean Diet and Low-Carb Eating: Six-Month Summary

I started my Ketogenic Mediterranean Diet on September 1, 2009.  After two months, I stopped compulsive record-keeping and food measurement and made a few other intentional tweaks: fish five times a week instead of seven miminum, more nuts (often two ounces a day—I like nuts and they’re convenient), less salad, more dark chocolate.  Otherwise the last four months have been similar to the initial two months of strict KMD.  My daily digestible carbohydrate intake has probably crept up to 40 g compared to 20-25 g on the strict KMD—this is still considered very low-carb. 

Accomplishments

Starting weight was 170 pounds (77.3 kg) on September 1.   After two months—8.6 weeks—my weight clearly stabilized at 155 lb (70.5 kg).  I lost the 15 lb (6.8 kg) over the first six weeks then just hovered around 155 lb.  So average weekly weight loss over the six weeks was 2.5 pounds.  Also lost a couple inches (5 cm) off my waist.

For the last four months—November through February—I’ve been eating the aforementioned liberalized KMD.  Weight has stayed around 155-157 lb (71 kg).  No calorie counting.  I eat as much as I want, except for carbs.  The experience of the first two months taught me how to eat 20-25 g of carbs in a day; it’s the gauge by which I estimate I’m eating 40 g daily now.

Has It Been Easy?

Yeah, relatively easy.  Two other adults in my house are also eating low-carb, which definitely helps.  Blogging here also helps me maintain compliance.  I promised myself to report everything—the good, the bad, and the ugly—honestly.  Accountability is important. 

Staying with the program may be easier for me than for others because I am heavily invested in it, psychologically and time-wise. 

It’s also been helpful for me to participate at two low-carb online communities: LowCarbFriends and Active Low-Carber Forums.  We support each other.  Thanks, guys.

I took diet holidays twice, for three days at both Thanksgiving and Christmas.  Gained three to five pounds (1.8 kg) each time on high-carb eating, but lost it over the next week by returning to the strict KMD.

Any Surprises?

Induction flu.  I’d never heard of it before.  Occurs typically on days 2–5 of very low-carb dieting: achiness and fatigue.  Others also experience headaches and dizziness, and it may last 1–2 weeks.

Rapid weight gain during my diet holidays (aka cheat days).  I was not gorging.  I figure the weight was mostly new glycogen in liver and muscle.  And water.

Eating fish more than once a day is a lot of fish!  Quickly boring, even unappetizing.  But that’s just me.  I need to be a more creative.  Most of my fish lately has been canned tuna.

Assuming that the Daily Values of various nutrients recommended by the U.S. Food and Drug Administration are valid, the KMD foods come up short in many vitamins and minerals.  I bet this is an issue (a problem?) with many, if not most, very low-carb diets if supplements aren’t used.  Those Daily Values are debatable, of course.  For instance, Gary Taubes argues that you don’t need much vitamin C if eating few carbs.  My nocturnal leg cramps and constipation were proof enough for me that I needed at least some supplements.  The recommended KMD supplements remedy the DailyValue shortfall in vitamins and minerals.  Dr. Richard K. Bernstein has a 30-gram carbohydrate diet for his diabetic patients and himself, as outlined in his Diabetes Solution book: no supplements are required.  

As time passes, I worry less about getting enough of various micronutrients.   I feel fine.  I’m still taking the recommended KMD supplements (5 pills a day) plus sugar-free Metamucil.   

I never had hunger that I couldn’t satisfy within the guidelines of the diet. 

No major trouble with cravings or longing for carbs.  I’ve gone six months now without whole grain bread, oatmeal, pizza, and pasta—very unusual for me.  I’d be OK never eating them again.  What I do miss are sweet, often fat-laced, carbohydrates: pie, cookies, cinnamon rolls, candy bars, cake, ice cream.  I doubt that desire will ever disappear, although it does for some who eat very low-carb.   

I counted calories only during the first two months of this experiment.  Remember, fats and proteins are unlimited.  Nevertheless, I ate fewer calories than my baseline intake.   This calorie reduction is a well-documented effect of very low-carb diets.  Fats and proteins are more satiating than carbohydrates.  It’s possible I’ve limited total calories subconsciously. 

[An interesting experiment would be to try to gain weight by over-eating fats and proteins while keeping total digestible carbs under 30 g/day.  Has it been done already?]

What’s Next?

I’d like to answer some intriguing questions.

Why did my weight loss stop where it did, at 155 lb (70.5 kg)? 

If I’d started the KMD at 270 lb (123 kg) instead of 170 lb (77.3 kg), would my weight loss have stopped at 255 lb (116 kg), 210 lb (95.5 kg) or 155 lb (70.5 kg)? 

Will two people, 300 lb each (136 kg), end up at the same final weight when following the program religiously?  Probably not, but why not?    

Six months ago, I believed many scientific studies supported the idea that a higher intake of carbohydrates is healthier, long-term, than the very low-carb Ketogenic Mediterranean Diet and other very low-carb diets.  Studies seemed to support higher carbohydrate intake in the form of traditional fruits, vegetables, legumes, and whole grains.  After reviewing the scientific literature over the last few months, I’m not so sure that higher carb consumption is necessary or beneficial for long-term health and longevity.  The evidence is weak.  Nearly all the pertinent studies are observational or epidemiologic—not the most rigorous science. 

On the other hand, I still can’t help feeling that the recommended eating styles of people like Monica Reinagel, Darya Pino, and Holly Hickman may be healthier than the KMD over the long run, at least for people free of diabetes and prediabetes.  What features unify those three?  Food that is minimally processed, fresh, locally produced when able, including a variety of fruits, vegetables, nuts, whole grains, and legumes. 

It seems that the human body is marvelously designed to survive, even thrive, with multiple ways of eating—but not all ways.   

The strongest evidence for higher carb consumption supports whole grains as a preventative for heart disease (coronary artery disease).  But the effect is modest. 

The argument against higher carb consumption is simple for people with diabetes and prediabetes: carbs raise blood sugar levels, sometimes to an unhealthy degree.  

I don’t see much role for highly processed, refined carbohydrates except as a cheap source of energy (calories).

What’s next for me is to formalize an opinion on which carbs, if any, and in what amount, to add back into the diet of those who have lost weight with the Ketogenic Mediterranean Diet.  The answer will probably be different for two groups:

  1. those who have diabetes, prediabetes, or metabolic syndrome
  2. healthy people who just need to control weight

The goal is to maximize health and longevity without tipping over into excessive carb intake that leads to overweight and obesity with associated illnesses.  

The traditional Mediterranean diet—long associated with health and longevity—is rich in carbohydrates.  The Ketogenic Mediterranean Diet—much lower in carbs—has great potential to help with loss of excess weight and control of blood sugar levels.  Does the KMD incorporate enough of the healthy components of the Mediterranean diet?  We may never know for sure.

Steve Parker, M.D.

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February 6, 2010 · 2:00 AM

What Is Normal Blood Sugar?

Lately I’ve been thinking about which carbohydrates might be added to the Ketogenic Mediterranean Diet to make it healthier yet remain diabetic-friendly.  Carbohydrates—some more than others—tend to elevate blood sugars in diabetics.  If I’m going to recommend adding carbs to the KMD, I have to give some idea what an acceptable blood sugar response would be.  An excessive rise in blood sugar level would necessitate eliminating that carbohydrate, reducing the serving size, or changing the diabetic medication regimen (increase a dose or add a new drug?) 

First off, I’ve reviewed what constitutes blood sugar levels in healthy non-diabetics before and after meals.  Those levels might give us some idea what to shoot for in diabetics. 

The following numbers refer to average blood sugar (glucose) levels in venous plasma, as measured in a lab.  Portable home glucose meters measure sugar in capillary whole blood.  Many, but not all, meters in 2010 are calibrated to compare directly to venous plasma levels.

Fasting blood sugar after a night of sleep and before breakfast: 85 mg/dl (4.72 mmol/l)

One hour after a meal: 110 mg/dl (6.11 mmol/l)

Two hours after a meal: 95 mg/dl (5.28 mmol/l)

Five hours after a meal: 85 (4.72 mmol/l)

(The aforementioned meal derives 50–55% of its energy from carbohydrate)

♦   ♦   ♦

Ranges of blood sugar for young healthy non-diabetic adults:

Fasting blood sugar: 70–90 mg/dl (3.89–5.00 mmol/l)

One hour after a typical meal: 90–125 mg/dl (5.00–6.94 mmol/l)

Two hours after a typical meal: 90–110 mg/dl (5.00–6.11 mmol/l)

Five hours after a typical meal: 70–90 mg/dl (3.89–5.00 mmol/l)

♦   ♦   ♦

Another way to consider normal blood sugar levels is to look at a blood test called hemoglobin A1c, which is an indicator of average blood sugar readings over the prior three months.  The average healthy non-diabetic adult hemoglobin A1c is 5% and translates into an average blood sugar of 100 mg/dl (5.56 mmol/l).  This will vary a bit from lab to lab.  Most healthy non-diabetics would be under 5.7%.

What Level of Blood Sugar Defines Diabetes and Prediabetes?  

According to the 2007 guidelines issued by the American Association of Clinical Endocrinologists:

Prediabetes (or impaired fasting glucose): fasting blood sugar 100–125 mg/dl (5.56–6.94 mmol/l)

Prediabetes (or impaired glucose tolerance): blood sugar 140–199 mg/dl (7.78–11.06 mmol/l) two hours after ingesting 75 grams of glucose

Diabetes: blood sugar 200 mg/dl (11.11 mmol/l) or greater two hours after ingesting 75 grams of glucose

Diabetes: random blood sugar 200 mg/dl (11.11 mmol/l) or greater, plus symptoms of diabetes

For my current thoughts on blood sugar goals for diabetics and prediabetics, please see the bottom half  of my “What is Normal Blood Sugar” page.

Steve Parker, M.D.

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January 10, 2010 · 2:00 AM

Diabetes + Overweight and Obesity = Diabesity

Mark Hyman, M.D., blogged about diabesity at the Huffington Post December 24, 2009.  He defines diabesity as a problem with glucose regulation associated with overweight and obesity.  The glucose physiology problem ranges from metabolic syndrome to prediabetes to full-blown type 2 diabetes.

“Diabesity” has been in circulation for a few years, but hasn’t caught on yet. 

What interested me about his blog post was that he advocates the Mediterranean diet as both therapeutic and prophylactic.  To quote Dr. Hyman:

The optimal diet to prevent and treat diabesity includes:

  • Fruits
  • Vegetables
  • Nuts
  • Seeds
  • Beans
  • Whole grains
  • Healthy fats such as olive oil, nuts, avocados, and omega-3 fats
  • Modest amounts of lean animal protein including small wild fish such as salmon or sardines

This is commonly known as a Mediterranean diet.  It is a diet of whole, real, fresh food. It is a diet of food you have to prepare and cook from the raw materials of nature.  And it has broad-ranging benefits for your health.

Food for thought, no doubt. 

Steve Parker, M.D.

Reference:  Hyman, Mark.  The diabesity epidemic part III:  Treating the real causes instead of the symptoms.  The Huffington Post, December 24, 2009

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January 5, 2010 · 2:00 AM

One of Every Three Born in 2000 Will Develop Diabetes

"No diabetes in my future!"

The U.S. already has 24 million people with diabetes and another 54 million with prediabetes.  Approximately one of every three persons born in the U.S. in 2000 will develop diabetes in his or her lifetime, according to the Centers for Disease Control and Prevention.

Incredible.

And largely preventable if we have the will.

Steve Parker, M.D.

Reference: Prediabetes FAQs at the CDC website.

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December 18, 2009 · 4:18 PM

Low-Carb Killing Spree Continues

The choice is clear . . . NOT

Low-fat and low-carb diets produce equal weight loss and improvements in insulin resistance but the low-carb diet may be detrimental to vascular health, according to a new study in Diabetes.

Methodology

Researchers in the the UK studied 24 obese subjects—15 female and 9 male—randomized to eat either a low-fat (20% fat, 60% carbohydrate) or low-carb (20% carb, 60% fat) diet over 8 weeks.  Average age was 39; average body mass index was 33.6.  Most of them had prediabetes.  Food intake was calculated to result in a 500 calorie per day energy deficit (a reasonable reduced-calorie diet, in other words).  Study participants visited a nutritionist every other day, and all food was provided in exact weighed portions. 

Results

Both groups lost the same amount of weight, about 7.3% of initial body weight. 

Triglycerides dropped by a third in the low-carb group; unchanged in the low-fat cohort.  Changes in total cholesterol, LDL cholesterol, and HDL changes were about the same for both groups.

Systolic blood pressure dropped about 10 points in both groups; diastolic fell by 5 in both.

“Aortic augmentation index” fell significantly in the low-fat group and tended to rise in the low-carb group.  According to the researchers, the index is used to estimate systemic arterial stiffness.  [In general, flexible arteries are better for you than stiff ones.  “Hardening-of-the-arteries,” etc.]  The low-fat group started with a AAI of 17, the low-carb group started at 12.  They both ended up in the 13-14 range. 

Peripheral insulin sensitivity improved significantly only in the low-carb group but “there was no significant difference between groups.”  No difference between the groups in hepatic (liver) insulin resistance. 

Fasting insulin levels fell about 20% in the low-fat group and about 40% in the low-carb group, a difference not reaching statistical significance (p=0.17).

The Authors’ Conclusions

This study demonstrates comparable effects on insulin resistance of low-fat and low-carbohydrate diets independent of macronutrient content.  The difference in augmentation index may imply a negative effect of low-carbohydrate diets on vascular risk.

My Comments

Yes, you can indeed lose weight over eight weeks on both low-fat and low-carb diets, if you follow them.  So diets DO work.  No surprise.

Loss of excess body fat by either method lowers your blood pressure.  No surprise.

Once again, concerns about low-carb/high-fat diets adversely affecting common blood lipids—increasing heart disease risk—are not supported.  No surprise

Hyperinsulinemia and insulin resistance are risk factors for development of diabetes and cardiovascular disease.  Results here tend to favor the low-carb diet.  I have to wonder if a study with just twice the number of test subjects would have shown a clear superiority for the low-carb diet.

The authors imply that aortic augmentation index is an important measure in terms of future cardiovascular health.  A major conclusion of this study is that a change in this index with the low-carb diet might adveresly affect heart health.  Yet they don’t bother to discuss this test much at all.  I’m no genius, but neither are the typical readers of Diabetes.  I doubt that they are any more familiar with that index than am I, and I’d never heard of it before. 

[Feel free to educate me regarding aortic augmentation index in the comment section.]

Unfortunately, many readers of this journal article and the associated news releases will come away with the impression, once again, that low-carb diets are bad for your heart. 

I’m not convinced.

Steve Parker, M.D.   

References:

Bradley, Una, et al.  Low-fat versus low-carbohydrate weight reduction diets.  Effects on weight loss, insulin resistance, and cardiovascular risk: A randomized control trial.  Diabetes, 58 (2009): 2,741-2,748.

Nainggolan, Lisa.  Low-carb diets hit the headlines again.  HeartWire, December 11, 2009.

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June 25, 2009 · 2:00 AM

Mediterranean Diet Cuts Risk of Diabetes After Heart Attack

In a blog post last year I discussed how the Mediterranean diet reduces the incidence of type 2 diabetes in healthy people.  I found another scientific journal article that examined the effect of various lifestyle factors that might influence the onset of type 2 diabetes in a different population: people who have had a recent heart attack.

Dariush Mozaffarian and colleauges studied 8291 Italians who had suffered a heart attack within the previous three months, but who did not have diabetes at the time of the heart attack.  Each study participant was followed for an average of 3.2 years to see if diabetes developed.  The researchers devised a Mediterranean diet score (range 0-15) incorporating consumption of cooked and raw vegetables, fruit, fish  and olive oil.  They also looked at consumption of butter, oils other than olive oil, cheese, wine, and coffee.  Participants’ dietary habits were assessed and scored three times over 1.5 years.  A number of other demographic, clinical, and lifestyle risk-factors were assessed.

The study did not survey other components of the Mediterranean diet, such as legumes, nuts, and grains.  This is a weakness of the study.  I suspect it relates to the fact they were using information from the GISSI-Prevenzione study, which was designed to evaluate fish oil and vitamin E in people who had had a heart attack, and researchers did not want to burden outpatient cardiology offices with full-scale questionnaires.

Over the three years of the study, 12% of participants developed new-onset diabetes, or 3.7% per year.  If not for the recent heart attack, the expected incidence rate for development of diabetes would be roughly 1.2% per year.  An even larger percentage, over 25%, of participants developed impaired fasting glucose, a kind of prediabetes that often develops into full-blown diabetes over time.

Was there anything about the people who developed diabetes that distinguished them from those who did not?  Yes – they tended to have older age, higher body mass index, high blood pressure, and they smoked.  Current smoking was associated with a 60% higher risk.  Every unit of higher body mass index, e.g, going from BMI 26 to 27, increased the risk by 9%.  High blood pressure increased the risk by 22%.

What about Mediterranean diet score?  The higher Mediterranean diet scores – score of 11-15 compared to 0-5 – were associated with 35% lower risk of diabetes.  A reduction in onset of impaired fasting glucose was similar.

The authors cite another study of 2499 patients with stable angina pectoris or remote heart attack (over 6 months perviously).  Twenty-two percent of them (one in five) developed diabetes or impaired fasting glucose over six years of follow-up, a rate of 4.1% per year.

The researchers write:

The lower risk associated with a Mediterranean-type diet suggests that diet could help reduce incidence of prediabetes and diabetes after a myodcardial infarction.  Many, though not all, trials have indicated that a Mediterranean-type diet lowers risk factors linked to insulin resistance and diabetes, including serum triglycerides, HDL cholesterol, systemic inflammation, endothelial function, and insulin sensitivity.  These physiological effects in short-term randomized trials provide biological plausibility for the inverse association between consumption of a Mediterranean-type diet and incidence of [impaired fasting glucose] and diabetes in this study.

What are the take-home points of this study for people – Italians, at least – who have had a recent heart attack?

  1. A recent heart attack is a risk factor for development of diabetes and prediabetes.
  2. The risk of developing diabetes and prediabetes may be significantly reduced by smoking cessation, prevention of weight gain, and consumption of typical Mediterranean foods.

Patients with both heart attacks and diabetes  have significantly worse outcomes  than people with only one of these conditions.  Since we can prevent many cases heart attack and diabetes through diet modification, why not?

Steve Parker, M.D.

Reference:  Mozaffarian, Dariush, et al.  Incidence of new-onset diabetes and impaired fasting glucose in patients with recent myocardial infarction and the effect of clinical and lifestyle risk factors.  Lancet, 370 (2007) 667-675.

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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 22, 2009 · 2:00 AM

Do Vitamin D and Calcium Supplements Cut Risk of Diabetes?

Cliffs of Dover: Pure White Calcium Carbonate

Cliffs of Dover: Pure White Calcium Carbonate

Several studies have associated vitamin D and calcium intake with lower risk of developing type 2 diabetes.  After reading that the Institute of Medicine in 2010 will probably increase the recommended amounts of vitamin D for every one, I decided to review the literature pertinent to diabetes.

Over the last 10 years, studies have associated low blood levels of vitamin D with a higher risk of cardiovascular disease, death, type 2 diabetes, some cancers, infections, autoimmune diseases, frequent falls in the elderly, and dementia.

The Institute of Medicine (in the U.S.) currently recommends 200 IU (international units) per day for people under 50, 400 IU for people 50-70, with an upper intake level of 2,000 IU per day.  I assume those amounts refer to a combination of food (or supplements) and the vitamin D your skin makes (but how do we know that?). 

The new recommendation is expected to be around 1,000-2,000 IU per day.  It’s quite difficult to get close to that just with food.  With adequate sun exposure, we can make some vitamin D.  But the dermatologists have scared us out of the sun with horror stories of skin cancer.  I’ve seen some tragic cases in my own patients.  Skin covered with sunscreen doesn’t make vitamin D.  It can be difficult to get enough sun exposure, especially at higher latitudes in winter

I reviewed scientific articles pertinent to tyepe 2 diabetes via PubMed and list the best ones for you below.   The evidence in favor of using vitamin D and calcium supplements to prevent diabetes is weak, but may be correct. 

I found nothing to suggest that high vitamin D and calcium intake (whether food or supplements) helps control established cases of diabetes. 

Take-Home Points 

If you want to prevent type 2 diabetes with supplements, 1000 IU of vitamin D and 800-1000 mg of elemental calcium daily might help.  The evidence is not strong.  It might help; it might not.  But it’s unlikely to hurt.  Check with your personal physician first.  More studies are needed.  Calcium supplements are routinely recommended by expert nutrition panels for people over 60 to prevent osteoporosis.  The vitamin D supplement may be healthy in other ways.

Who, in particular, might want to prevent type 2 diabetes?  People with . . .

I’m sufficiently convinced about the nondiabetic vitamin D benefits that I’m going to start taking 1,000 IU per day.

Steve Parker, M.D.,

References:

Pittas, Anastassios, et al.  The effects of calcium and vitamin D supplementatinon on blood glucose and markers of inflammatin in nondiabetic adults.  Diabetes Care, 30 (2007): 980-9896.

Chowdhurry, T.A., et al.  Vitamin D and type 2 diabetes: Is there a link?  Primary Care Diabetes, April 21, 2009 (Epub ahead of print).

Pittas, Anastassios, et al.  Vitamin D and calcium intake in relation to type 2 diabetes in women.  Diabetes Care, 29 (2006): 650-656.

Knept, P., et al.  Serum vitamin D and subsequent occurrence of type 2 diabetes.  Epidemiology, 19 (2008): 666-671.

de Boer, I.H., et al.  Calcium plus vitamin D supplementation and hte risk of incident diabetes in the Womens’ health Initiative.  Diabetes Care, 31 (2008): 701-707. (Epub January 30, 2008).

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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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