Category Archives: Overweight

Do Vegetables and Fruits Prevent Disease?

Posted on June 29, 2013 | Comments Off on Do Vegetables and Fruits Prevent Disease?
Switching to the paleo diet often leads to increased vegetable and fruit consumption

Switching to the paleo diet often leads to increased vegetable and fruit consumption

Potential answers are in the American Journal of Clinical Nutrition (2012).  I quote:

For hypertension, coronary heart disease, and stroke, there is convincing evidence that increasing the consumption of vegetables and fruit reduces the risk of disease. There is probable evidence that the risk of cancer in general is inversely associated with the consumption of vegetables and fruit. In addition, there is possible evidence that an increased consumption of vegetables and fruit may prevent body weight gain. As overweight is the most important risk factor for type 2 diabetes mellitus, an increased consumption of vegetables and fruit therefore might indirectly reduces the incidence of type 2 diabetes mellitus. Independent of overweight, there is probable evidence that there is no influence of increased consumption on the risk of type 2 diabetes mellitus. There is possible evidence that increasing the consumption of vegetables and fruit lowers the risk of certain eye diseases, dementia and the risk of osteoporosis. Likewise, current data on asthma, chronic obstructive pulmonary disease, and rheumatoid arthritis indicate that an increase in vegetable and fruit consumption may contribute to the prevention of these diseases. For inflammatory bowel disease, glaucoma, and diabetic retinopathy, there was insufficient evidence regarding an association with the consumption of vegetables and fruit.

It bothers me that vegetables and fruits are lumped together: they’re not the same.

The paleo diet is unfairly characterized as meat-centric. It can certainly provide beaucoup vegetables and fruits. Diabetics should be careful which ones they choose, to avoid spikes in blood sugar.

Steve Parker, M.D.

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Ancestral Diet May Improve Diabetes in Pima Indians

Posted on November 1, 2012 | 2 comments

Saguaro cactus fruit is edible

I ran across a 1991 New York Times article by Jane Brody discussing the benefits to Pima Indians of returning to their ancestral diet.  The Pima have major problems with obesity and diabetes.  (I frequently treat Pima Indians in the hospital.)  Some quotes:

Studies strongly indicate that people who evolved in these arid lands are metabolically best suited to the feast-and-famine cycles of their forebears who survived on the desert’s unpredictable bounty, both wild and cultivated.

By contrast, the modern North American diet is making them sick. With rich food perpetually available, weights in the high 200’s and 300’s are not uncommon among these once-lean people. As many as half the Pima and Tohono O’odham (formerly Papago) Indians now develop diabetes by the age of 35, an incidence 15 times higher than for Americans as a whole. Yet before World War II, diabetes was rare in this population.

Pima Indians traditionally ate a diet of tepary beans, mesquite seeds, corn, grains, greens, and other high-fiber/low-fat foods.  The switch to a diet high in sugar, refined grains, and other highly processed convenience foods may well be responsible for the current high rates of obesity and diabetes.  Australian aborigines have the same problem.

Steve Parker, M.D.

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Posted in Genetics, Grains, Overweight, Paleo Diet

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Are We Fat Because We’re Less Active?

Posted on October 5, 2012 | Comments Off on Are We Fat Because We’re Less Active?

Less active

Much of the world has seen a significant decline in populaton-wide physical activity over the last few decades, according to Nike-sponsored research reported in Obesity Reviews.

Countries involved with the study are the U.S., U.K., Brazil, China, and India.  How did they measure activity levels?

Using detailed historical data on time allocation, occupational distributions, energy expenditures data by activity, and time-varying measures of metabolic equivalents of task (MET) for activities when available, we measure historical and current MET by four major PA domains (occupation, home production, travel and active leisure) and sedentary time among adults (>18 years).

The authors note the work of Church, et al, who found decreased work-related activity in the U.S. over the last half of the 20th century.

Inexplicably, they don’t mention the work of Westerterp and colleagues who found no decrease in energy expenditure in North American and European populations since the 1980s.

More active

My gut feeling is that advanced populations around the globe probably are burning fewer calories by physical activity over the last 50 years, if not longer, thanks to technologic advances.  We in the U.S. are also eating more calories lately.  Since the 1970s, average daily consumption by women is up by 150 calories, and up 300 by men.  I’m surprised we’re not fatter than we are.

Steve Parker, M.D. 

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Prediabetes and Diabetes on the March in U.S. Adolescents

Posted on August 24, 2012 | Comments Off on Prediabetes and Diabetes on the March in U.S. Adolescents

The June, 2012, issue of Pediatrics has an article stating that the incidence of diabetes and prediabetes in U.S. adolescents increased from 9% in 1999 to 23% in 2008.  The finding is based on the NHANES survey of 12 to 19-year-olds, which included a single fasting blood sugar determination.

The investigators offered no solution to the problem.  I’m no pediatrician, but my educated guess is that the following measures would help prevent adolescent type 2 diabetes and prediabetes:

  • more exercise
  • eat less refined starches and sugar
  • maintain body weight in the healthy range
I’m sure many of the adolescent type 2 diabetics and prediabetics are overweight or obese.  A 2010 study out of Colorado found a low-carbohydrate, high-protein diet safe and effective for adolescents.  Fortunately, the decades-long ascent of the adolescent obesity rate in the U.S. seems to have peaked for now.
The paleo diet would restrict consumption of concentrated sugars and refined starches, but it’s hard to get adolescents to skip those items.

Steve Parker, M.D.

PS: I scanned the article quickly and don’t remember if the researchers broke down the diabetes cases by type 1 and type 2.  I’d be shocked if type 1 diabetes rose this much over the last decade.

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Are Dense Acellular Carbohydrates the Primary Cause of Obesity?

Posted on July 31, 2012 | Comments Off on Are Dense Acellular Carbohydrates the Primary Cause of Obesity?

That’s a proposal in a recent scientific article, from which I quote:

The present hypothesis suggests that in parallel with the bacterial effects of sugars on dental and periodontal health, acellular flours, sugars, and processed foods produce an inflammatory microbiota via the upper gastrointestinal tract, with fat able to effect a “double hit” by increasing systemic absorption of lipopolysaccharide. This model is consistent with a broad spectrum of reported dietary phenomena. A diet of grain-free whole foods with carbohydrate from cellular tubers, leaves, and fruits may produce a gastrointestinal microbiota consistent with our evolutionary condition, potentially explaining the exceptional macronutrient-independent metabolic health of non-Westernized populations, and the apparent efficacy of the modern “Paleolithic” diet on satiety and metabolism.

You can read the whole shebang free online.

Steve Parker, M.D.

Bacteria in Petri dish

Reference:  Spreadbury, Ian.  Comparison with ancestral diets suggests dense acellular carbohydrates promote an inflammatory microbiota, and may be the primary dietary cause of leptin resistance and obesity.Diabetes Metab Syndr Obes. 2012; 5: 175–189. Published online 2012 July 6. doi:  10.2147/DMSO.S33473 PMCID: PMC3402009

 

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Posted in Overweight, Paleo Theory

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We’re Fat Because We Eat Too Much

Posted on July 25, 2012 | Comments Off on We’re Fat Because We Eat Too Much

At least one group of hunter-gatherers doesn’t burn any more calories in physical activity than Western cultures.  So much for blaming our fatness on low activity levels and labor-saving technology.

Cliff Notes version from the BBC.

—Steve

h/t Colby Vorland at nutsci.org

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Is Fructose the Cause of Obesity?

Posted on June 3, 2012 | 2 comments

Mainly because of its low cost, HFCS [high fructose corn syrup] consumption replaced approximately one-third of the total sugar consumption in the USA between 1970 and 2000, paralleling to some extent the increasing prevalence of obesity during this period. Consequently, HFCS has been a particular focus of possible blame for the obesity epidemic. However, HFCS consumption has remained very low in other parts of the world where obesity has also increased, and the most commonly used form of HFCS contains about 55% fructose, 42% glucose, and 3% other sugars, and hence is associated with similar total fructose and glucose intakes as with sugar. Furthermore, sucrose is hydrolyzed in the gut and absorbed into the blood as free glucose and fructose, so one would expect HFCS and sucrose to have the same metabolic consequences. In short, there is currently no evidence to support the hypothesis that HFCS makes a significant contribution to metabolic disease independently of the rise in total fructose consumption.

 

Given the substantial consumption of fructose in our diet, mainly from sweetened beverages, sweet snacks, and cereal products with added sugar, and the fact that fructose is an entirely dispensable nutrient, it appears sound to limit consumption of sugar as part of any weight loss program and in individuals at high risk of developing metabolic diseases. There is no evidence, however, that fructose is the sole, or even the main factor in the development of these diseases…

— Luc Tappy in BMC Biology, May 21, 2012 (the article is a review of fructose metabolism and potential adverse effects of high consumption)

PS: Luc Tappy believes that excessive calorie consumption is an important cause of overweight and obesity.

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Sources of Calories in U.S. Diet Over Last Four Decades

Posted on March 20, 2012 | 3 comments

Italian seaside totally unrelated to this post

Do you ever wonder how many of the total calories in the aveage U.S. diet come from added sugars? Grains? Dairy products? Added fats?

You’d have to do some detailed nutrient analysis to get your personal numbers, but if you’d like U.S. averages, see this cool infographic at Civil Eats.

The graph also shows how many calories are or were available for consumption per capita over time (without accounting for wastage in restaurants). It’s based on U.S. Department of Agriculture data.

A superficial glance suggests that U.S. per capita daily calorie consumption has increased by about 600 from the 1970s until now. But remember, these numbers don’t discount for restaurant wastage. Nor do I see an adjustment for children versus adults. I’ve seen other calculations of an extra daily 150 calories (women) to 300 calories (men). Even the lower numbers could explain our explosion of overweight and obesity.

Steve Parker, M.D.

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Posted in Dietary Fat, Grains, Overweight

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Is the “Calories In/Calories” Theory Outdated?

Posted on January 23, 2012 | 3 comments

Not watching The Biggest Loser

Dr. Barry Sears (Ph.D., I think) recently wrote about a lecture he attended by a dietitian affiliated with “The Biggest Loser” TV show.  She revealed the keys to weight-loss success, at least on that show.  Calorie restriction is a major feature, with the typical 300-pounder (136 kg) eating 1,750 calories a day. 

On my Advanced Mediterranean Diet, 300-pounders get 2,300 calories (men) or 1,900 calories (women). 

Although not stressed by Dr. Sears, my impression is that contestants exercise a huge amount. 

Go to the Sears  link above and you’ll learn that all contestants are paid to participate.  In researching my Conquer Diabetes and Prediabetes book, I learned that the actual Biggest Loser wins $250,000 (USD).  Also, “The Biggest Loser” is an international phenomenon with multiple countries hosting their own versions, with different pay-off amounts.  A former winner, Ali Vincent, lives in my part of the world and still has some celebrity status.

This TV show demonstrates that the calories in/calories out theory of body weight still applies, including the fact that massive exercise can help significantly with weight loss.  In real-world situations, exercise contributes only a small degree to loss of excess weight. 

The major take-home point of the show, for me, is that you can indeed make food and physical activity choices that determine your weight.

Most of us watch too much

I know losing 50 to 10o pounds of fat (25–45 kg) and keeping it off for a couple years is hard; most folks can’t do it.  Do you think you’d be more successful if I gave you $250,ooo for your success?

Steve Parker, M.D.

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Posted in Exercise, Overweight, Weight Loss

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