Category Archives: Overweight and Obesity

November 10, 2009 · 2:00 AM

Low-Carb Ketogenic Diet Beats Low-Glycemic Index Diet in Overweight Type 2 Diabetes

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Avoid the needle with a low-carb ketogenic diet

Duke University (U.S.) researchers demonstrated better improvement and reversal of type 2 diabetes with an Atkins-style diet, compared to a low-glycemic index reduced-calorie diet.

Methodology

Ninety-seven overweight and obese adults, 78% women and 40% black, were randomly assigned to either:

  • a very low-carb ketogenic diet (Atkins induction phase, as in Atkins Diabetes Revolution) or
  • a low glycemic-index index calorie-restricted diet (The GI Diet by Rick Gallop). 

Thirty-eight were in the Atkins group; 46 in the low-glycemic index (low-GI) group.  Seventeen dropped out of each group before the end of the 24-week study.  Average weight was 234.3 pounds (106.5 kg); average body mass index was 37.  The Atkins group averaged 13% of total calories from carbohydrate; the low-GI cohort averaged 44%. 

Results

Both groups lost weight and had improvements in hemoglobin A1c, fasting insulin, and fasting glucose. 

The Atkins group lowered their hemoglobin A1c by 1.5% (absolute drop, not relative) versus 0.5% in the other group. 

The Atkins group lost 11.1 kg versus 6.9 kg in the other group. 

The Atkins group increased HDL cholesterol by5.6 mg/dl versus no change in the other group. 

All the aforementioned comparisons were statistically significant. 

Diabetes medications were stopped or reduced in 95% of the Atkins group versus 62% of the low-GI group.

Total and LDL cholesterol levels were unchanged in both groups. 

Triglycerides fell significantly only in the Atkins group.

My Comments

You may be interested to know that this study was funded by the Robert C. Atkins Foundation.

One strength of this study is that it lasted for 24 months.  Many similar studies last only eight to 12 weeks.  A drawback is that, with all the drop-outs,  the number of participants is low. 

The GI Diet performed pretty well, too, all things considered.  Sixty-two percent reduction or elimination of diabetes drugs—not bad.  For a six-year-old book, it’s still selling fairly well at Amazon.com.  That may be why they chose it as the comparison diet.

The diet with fewer carbohydrates—Atkins induction—was most effective for  improving control of blood sugars.  So effective, in fact, that the researchers sound a note of warning:

For example, participants taking from 40 to 90 units of insulin before the study were able to eliminate their insulin use, while also improving glycemic control.  Because this effect occurs immediately upon implementing the dietary changes, individuals with type 2 diabetes who are unable to adjust their own medication or self-monitor their blood glucose should not make these dietary changes unless under close medical supervision.  

[Not all insulin users were able to stop it.]

Overall, lipids were improved or unchanged in the Atkins group, despite the lack of limits on saturated fat intake.  A common criticism of the Atkins diet is that it has too much saturated fat, leading to higher total and LDL cholesterol levels, which might raise long-term cardiovascular risks.  Not so, here. 

When you reduce carbohydrate intake, the percentages of fat and protein in the diet also change.  In this Atkins diet, protein provided 28% of daily calories, and fat 59%.  In the low-GI diet, protein provided 20% of daily calories, fat 36%.  The beneficial effects of the Atkins diet probably reflect the low carbohydrate consumption rather than high protein and fat. 

The Atkins induction-phase diet was clearly superior to the low-glycemic index diet in this overweight diabetic sample, without restricting calories.

Steve Parker, M.D.

Reference:  Westman, Eric, et al.  The effect of a low-carbohydrate, ketogenic diet versus a low-glycemic index diet on glycemic control in type 2 diabetes mellitus.  Nutrition & Metabolism 2008, 5:36   doi:10.1186/1743-7075-5-36

Additional Reading

Samaha, F., 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.

Boden, G., et al.  Effect of a low-carbohydrate diet on appetite, blood glucose levels, and insulin resistance in obese patients with type 2 diabetes.  Annals of Internal Medicine, 142 (2005): 403-411.

Vernon, M., et al.  Clinical experience of a  carbohydrate-restricted diet: Effect on diabetes mellitus.  Metabolic Syndrome and Related Disorders, 1 (2003): 233-238.

Yancy, W., et al.  A pilot trial of a low-carbohydrate ketogenic diet in patients with type 2 diabetes.  Metabolic Syndrome and Related Disorders, 1 (2003): 239-244.

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August 2, 2009 · 2:25 AM

Medical Cost of Obesity Soars

Healthcare dollars

Healthcare dollars

A report released last week found that obese individuals in the U.S. spend an extra $1,429 yearly on healthcare compared to normal-weight people.  Furthermore, total U.S. cost of treating obesity-related conditions was $147 billion in 2008.

Unsure if you’re overweight or obese?  Find out with one of the body mass index calculators available on the Internet.

Are you obese and fed up with the extra expense?  Are you already suffering from overweight-related medical conditions?  If so, read my document on how to prepare for weight loss, then get started soon. 

Well-begun is half done.

Steve Parker, M.D.

Author of The Advanced Mediterranean Diet

Reference:  Finkelstein, E.A., et al.  Annual medical spending attributable to obesity: Payer and service-specific estimates.  Health Affairs, 28 (2009): w822-w831.

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July 5, 2009 · 2:00 AM

ADA Now Says Low-Carb Diets OK for Overweight Type 2 Diabetics

CB037166Eighty-five percent of type 2 diabetics are overweight or obese.  Overweight either causes or aggravates many cases of diabetes.

For the last quarter-century, many U.S. government agencies and healthcare organizations have advocated a low-fat diet for overweight people, including type 2 diabetics.  Recent studies have documented that low-carbohydrate diets can also be effective in weight loss.  Low-carb diets replace carbohydrates with either fats or proteins, or both.  The A to Z Weight Loss Study compared the Atkins, Ornish, LEARN, and Zone diets in 311 overweight pre-menopausal women.  The Atkins group tended to lose a bit more weight. Changes in lipid profiles, waist-hip ratios, fasting insulin and glucose levels, blood pressure, and percentage of body fat were comparable or better with Atkins versus the other diets.

The Amerian Diabetes Association now gives the go-ahead for use of low-carb diets as a weight-control method for type 2 diabetics.  Previously, the organization had recommended against diets that restrict carbohydrates to less than 130 grams daily.  (A baked potatoe without the skin has 30 grams.)  Understand that the ADA does not endorse low-carb diets for weight loss or diabetes management.  They simply say that either low-carb or low-fat calorie-restricted diets might be effective for up to one year.

I caution you that low-carb diets may be deficient in fiber, minerals, vitamins, and phytonutrients that may be very beneficial in terms of long-term health and longevity.

The tide has been turning against low-fat diets for the last six years.

Steve Parker, M.D.

Reference: American Diabetes Association.  Clinical Practice Recommendations 2008.  Diabetes Care, 31 (2008): S61-S78.

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July 3, 2009 · 2:00 AM

A Chance to Cut is a Chance to Cure

"Has anybody seen my pen?"

"Has anybody seen my pen?"

Gastric bypass is the most common bariatric surgery in the U.S.  The odds of dying from that procedure are roughly 1 in 200.  Thousands of people sign on the dotted line for it every year.  Why do they take that risk?

A recent study out of Sweden shows that people who undergo various bariatric surgeries reduce their risk of death over the next 11 years by 25%.

In the Swedish Obese Subjects Study, 2010 subjects underwent bariatric surgery and 2037 received conventional treatment.  Overall mortality was recorded over the next 11 years.  Only three of the subjects were lost to follow-up (unknown whether alive or not).  The average body mass index (BMI) for all subjects was 41.

Out of the conventional treatment group, 126 died.  In the surgery group, only 101 died.  Average weight change in the conventional treatment group was up or down only 2%.  People in the surgery group were given one of three operations: gastric bypass, vertical-banded gastroplasty, or banding.  After 10 years, average weight loss of the groups was 25%, 16%, and 14%, respectively.

Over the course of 11 years, people in the surgery group had 25% less chance of dying when compared to the conventional treatment group.  The most common causes of death were heart attacks and cancer.

Even better results were found back in the U.S.  Researchers in Utah looked at mortality rates of 7925 patients who had undergone gastric bypass surgery between 1984 and 2002.  They compared death rates to a control group (also 7925 people) of obese people who applied for driver’s licenses.  Subjects were matched for sex, body mass index, and age.  Average BMI of the surgical group was 45.

Over the course of seven years, there were 321 deaths in the control group and 213 in the surgery group.  Deaths from any cause were reduced by 40% in the surgery group, compare to the control group.  Surgery patients had less death from cardiovascular disease, diabetes, and cancer.

Surgery is definitely a roll of the dice.  Now you know why people play the game.

Steve Parker, M.D.

References:

Sjostrom, Lars, et al.  Effects of Bariatric Surgery on Mortality in Swedish Obese Subjects.  New England Journal of Medicine, 357 (2007):  741-752.

Adams, Ted, et al.  Long-Term Mortality after Gastric Bypass Surgery.  New England Journal of Medicine, 357 (2007): 753-761. 

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July 1, 2009 · 2:00 AM

Does Weight Loss Prevent Type 2 Diabetes?

Finger-pricking four times a day gets old real quick!

Finger-pricking four times a day gets old real quick!

I found an interesting statistic in a scientific journal article last year:

Every 2.2 pound (1 kg) loss of excess weight lowers the risk of developing type 2 diabetes by 16%.

That tidbit was embedded in another article with a focus on regain of lost weight over time.  The “16% per kilogram” number sounded too good to be true, and I had never heard it before.  So I did some digging and found the source of the statistic.  Ain’t the Internet wunnerful?

The origin of the 16% figure is the Diabetes Prevention Program Research Group.  Investigators enrolled 1,079 middle-aged (mean 50.6 years) study participants and followed them over 3 years, noting the effects of exercise, percentage of fat in the diet, and weight loss on the subsequent development of diabetes.  Average body mass index was 33.9.  (A 5-foor, 4-inch person weighing 197 pounds (89.5 kg) has a BMI of 33.9).  Sixty-eight percent of participants were women.  The investigators’ goal for this group of overweight people was for loss of 7% of body weight through diet, physical activity, and periodic counseling sessions.  Average weight loss over the course of three years was 9 pounds (4.1 kg).

None of the study participants had diabetes at the time of enrollment.  But, by design, they all had laboratory-proven “impaired glucose tolerance.”  Impaired glucose tolerance is a form of “pre-diabetes.”  It is determined by giving a  75-gram dose of glucose by mouth, then measuring blood glucose (sugar) 2 hours later.  A blood glucose level under 140 is normal.  If the level is 140-199, you have impaired glucose tolerance.

Having impaired glucose tolerance means that study participants’ glucose (sugar) metabolism was already abnormal.  They were at higher than average risk of developing diabetes, compared with both average-weight healthy people and overweight people without impaired glucose tolerance.  This is a great cohort to study for development of diabetes.  But the finding that “every 2.2 pounds of weight loss lowers the risk of diabetes by 16%” applies to this particular group with impaired glucose tolerance, not the general overweight population.

A total of 153 participants developed diabetes over the course of 3 years.  Loss of excess weight was by far the best predictor of lowered diabetes risk, compared with regular exercise and lowering percentage of dietary fat.

Yes, weight loss does prevent diabetes in some, probably many, overweight people.  The specific degree of reduced risk depends on numerous factors, such as age, sex, genetics, degree of weight loss, and pre-existing impaired glucose tolerance.

Steve Parker, M.D.

Reference: Hamman, Richard, et al.  Effect of Weight Loss With Lifestyle Intervention on Risk of Diabetes.  Diabetes Care, 29, (2006): 2,102-2,107.

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June 21, 2009 · 2:00 AM

Adverse Health Effects of Obesity

"I'm not fat, I'm chubby"

"I'm not fat, I'm chubby"

As a physician, I see many illnesses and conditions that are caused or aggravated by overweight and obesity.  Both terms refer to excess body fat; obesity is a greater degree of fat.

Body mass index (BMI) is used to define overweight and obesity.  Your BMI is your weight in kilograms divided by your height in meters squared.  A BMI between 18.5 and 25 is considered healthy.  BMIs between 25 and 30 are overweight.  Here’s an online BMI calculator.  For example, a 5-foot, 4-inch person enters obesity territory – BMI over 30 – when weight reaches 174 pounds (79 kilograms).  A 5-foot, 10-incher is obese starting at 208 pounds (94.5 kilograms).

People trying to lose excess fat typically have days when willpower, discipline, and commitment waver.  On those days, it can help to remember why they started this adventure in the first place.  The reasons for many involve improved health and longevity.  Even if you have just 20 pounds of excess fat to lose, it will often take twenty weeks.  Your weight-loss goal is one to one-and-a-half pounds a week. 

This race is won not by the swift, but by the slow and steady.

Here’s a laundry list of obesity-related conditions to remind you why you want to avoid obesity:

  • Premature death.  It starts at BMI of 30, with a major increase in premature death at BMI over 40.  The U.S. has 200,000 yearly deaths directly attributable to obesity.
  • Arthritis, especially of the knees.
  • Type 2 diabetes melllitus.  Eight-five percent of people with type 2 diabetes are overweight.
  • Increased cardiovascular disease risk, especially with an apple-shaped fat distribution as compared to pear-shaped.  Cardiovascular disease includes heart attacks, high blood pressure, strokes, and peripheral arterial disease (poor circulation).
  • Obstructive sleep apnea.
  • Gallstones are three or four times more common in the obese.
  • High blood pressure.  At least one third of cases are caused by excess body fat.  Every 20 pounds of excess fat raises blood pressure 2-3 points (mmHg).
  • Tendency to higher total and LDL cholesterol, higher triglycerides, while lowering HDL cholesterol.  These lipid changes are associated with hardening of the arteries – atherosclerosis – which can lead to heart attacks, strokes, and peripheral arterial disease.
  • Increased cancers.  Prostate and colorectal in men.  Endometrial, gallbladder, cervix, ovary, and breast in women.  Kidney and esophageal adenocarcinoma in both sexes.  Excess fat contributes to 14-20% of all cancer-related deaths in the U.S.  Over 550,000 people die from cancer in the U.S. yearly.  Twenty percent of us will die from cancer.
  • Strokes.
  • Low back pain.
  • Gout.
  • Varicose veins.
  • Hemorrhoids.
  • Blood clots in legs and lungs.
  • Surgery complications: poor wound healing, blood clots, wound infection, breathing problems.
  • Pregnancy complications: toxemia, high blood pressure, diabetes, prolonged labor, greater need for C-section.
  • Fat build-up in liver.
  • Asthma.
  • Low sperm counts.
  • Decreased fertility.
  • Delayed or missed diagnosis due to difficult physical examination or weight exceeding the limit of diagnostic equipment.

I hope you find this information motivational rather than depressing.  For those already obese, weight loss can significantly improve, alleviate, or prevent these conditions.  Many obesity-related medical conditions and metabolic abnormalities are improved with loss of just five or 10% of total body weight.  For instance, a 240 pound man with mild diabetes and high blood pressure may be able to reduce or avoid drug therapy by losing just 12 to 24 pounds.  He’s still obese, but healthier.

Steve Parker, M.D. 

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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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