Tag Archives: metabolic syndrome

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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Filed under Carbohydrate, ketogenic diet, Protein, Weight Loss

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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Filed under Causes of Diabetes, Prevention of T2 Diabetes

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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Filed under Carbohydrate, Overweight and Obesity, Weight Loss

Mediterranean Diet + Nuts = Reversal of Metabolic Syndrome

MPj04031620000[1]An article published December 8, 2008, by Bloomberg.com presents results of a recent scientific study in Spain that showed reduction in “metabolic syndrome” by the Mediterranean diet supplemented with nuts.  CBSnews.com, Reuters, and others helped spread the news.  The Bloomberg article was written by Nicole Ostrow.

Metabolic syndrome is a constellation of clinical factors that are associated with increased risk of type 2 diabetes and atherosclerotic complications such as heart attack and stroke.  [Sometimes metabolic sydrome is called Syndrome X, which I sorta like.  Oh, the mystery!]  One in six Americans have the syndrome.  Diagnosis requires at least three of the following five conditions:

  • High blood pressure (130/85 or higher, or using a high blood pressure medication)
  • Low HDL cholesterol:  under 40 mg/dl in a man, under 50 in a women (or either sex taking a cholesterol-lowering drug)
  • Triglycerides over 150 mg/dl (or taking a cholesterol-lowering drug)
  • Abdominal fat:  waist circumference 40 inches or greater in a man, 35 inches or greater in a woman
  • Fasting blood glucose over 100 mg/dl

The scientific study at hand is part of the PREDIMED study being conducted in Spain.  For this portion of the study, 1,224 participants at high risk for cardiovascular disease were randomized to follow a 1) low-fat diet (considered the control group), 2) Mediterranean diet plus 1 liter virgin olive oil per week, or 3) Mediterranean diet plus 30 gm daily of mixed nuts.

Note that the nuts used in this study were walnuts, almonds, and hazelnuts.  Half of all nuts were walnuts; a quarter of the nuts were almonds and a quarter were hazelnuts.

Participants were 55-80 years old, and 61% had metabolic syndrome at baseline.  Participants could eat all they wanted, and there was no increase in physical activity for any of the groups.  Participants were given instructions at baseline and quarterly.

After one year of intervention, the prevalence of metabolic syndrome  was reduced by 14% in the Mediterranean diet plus nuts group compared to the control, low-fat diet group.  The Mediterranean diet plus extra olive oil group reduced prevalence of metabolic syndrome by 7%, but this did not reach statistical significance (P=0.18).

New cases of metabolic syndrome continued to develop at about the same rate in all three groups.  I.e., incident rates were not significantly different.  So, the lower prevalence of metabolic syndrome after one year reflected reversion or clearing of the syndrome in many people who had it at baseline.  Compared to the control group, people in the nutty group were 70% more likely to resolve their metabolic syndrome.  Individuals in the oily group were 30% more likely than controls to resolve the condition.

[Feel free to consult a dictionary for definitions of “prevalence” and “incidence.”]

The researchers conclude that:

A traditional Mediterranean diet enriched with nuts could be a useful tool in the management of the metabolic syndrome. 

My Comments:

Thirty grams (daily) of nuts is a decent-sized snack of about 180 calories.  Thirty grams of almonds formed a heap in the palm of my hand, not touching my fingers.  This is more than the “two tablespoons” reported by CBSnews.com December 9.

If you have metabolic syndrome, you might want to try reversing it with all the usual methods (e.g., lose excess fat weight, exercise more) along with a traditional Mediterranean diet enriched with 30 gm of mixed nuts daily.  As usual, check with your personal healthcare provider first.  Be aware that many of them won’t know about this study.

The puzzling thing to me is:  If the Mediterranean diet plus extra nuts is so effective in reversing metabolic syndrome, why didn’t that study cohort see fewer new cases of metabolic syndrome?

Steve Parker, M.D., author of The Advanced Mediterranean Diet

Additional reference:  Salas-Salvado, Jordi, et al.  Effect of a Mediterranean Diet Supplemented With Nuts on Metabolic Syndrome Status: One-Year Results of the PREDIMED Randomized Trial.  Archives of Internal Medicine, 168 (2008): 2,449-2,458.

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Filed under Causes of Diabetes, Mediterranean Diet

Health Benefits of Nuts

You just don't see sickly squirrels.  Hmmm . . .

You just don't see sickly squirrels. Hmmm . . .

I frequently check in at CalorieLab for up-to-date nutrition news.

Karen Collins, M.S., R.D., C.D.N., was a guest contributor there March 14, 2009, writing about the potential health benefits of nuts.  I was aware of the cardiovascular benefits; she taught me about possible salutary effects on cancer and diabetes.

From my own literature review, the cardiac benefits are associated with a nut “dose” of three to five 1-ounce servings a week.

Last December, I blogged about reversal of metabolic syndrome with a Mediterranean Diet supplemented with nuts.

I recommend Ms. Collins’ article to you. 

Steve Parker, M.D.

Reference:  Albert, Christine, et al.  Nut consumption and decreased risk of sudden cardiac death in the Physicians’ Health StudyArchives of Internal Medicine, 162, (2002): 1,382-1,387.

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Filed under Health Benefits, Mediterranean Diet