Archive for May, 2012
May 31st, 2012
Claude Bouchard and colleagues have looked at six studies of physical activity and found that exercise actually made cardiometabolic risk factors worse for many subjects. The prevalence of adverse events for select risk factors was 8.3% for exercise training induced changes in fasting insulin, 10.4% for triglycerides, 12.2% for systolic blood pressure, and 13.3% for changes in high-density lipoprotein cholesterol (the good cholesterol). 7% of subjects had adverse increases in two or more cardiometabolic risk factors.
The six studies provided data on 1,687 adults. Adverse events were defined to exclude within-subject deviations over a given period of time. To establish this, the researchers studied 60 subjects who were measured three times over three weeks for each trait. This produced what they refer to as the technical error or TE. An adverse event was defined as 2 times the TE in a direction indicating a worsening of the risk factor. The risk factors measured were systolic blood pressure, triglycerides, fasting insulin, or decrease in HDL-C. PLOSOne: Adverse Metabolic Reaction to Exercise
The implications of this study are enormous. First, it appears on the front page of today’s New York Times, NYT:Kolata: Can exercise be bad for you, so it will get wide publicity. Second, it will spur more research on other cardiometabolic risk factors and exercise. But also, the paper points out that the response pattern to exercise aggregates in families. In fact, the authors point out, “the genetic component of a response trait can be defined in terms of RNA abundance observed in the sedentary state or by specific genomic variants. This suggests that it may be possible with further research to identify molecular predictors of the inability to benefit from regular exercise and of adverse changes in specific cardiometabolic and diabetes risk factors.
Third, the study is bound to have an impact on national recommendations for universal levels of physical activity. The one-size-fits-all recommendations must now take into account the adverse effects to a significant part of the population.
Finally, this is likely to throw the drug/device approval process at the Food and Drug Administration into some turmoil. Particularly with drugs, their safety and effectiveness is compared to a placebo group which is receiving a diet and exercise intervention. If some in the placebo group are showing a worsening of the cardiometabolic risk factors, it would make the drug look less effective. But overall, it raises the question, “If exercise were a drug, would the FDA approve it for treating obesity?” Given the current environment, the answer is clearly no. Thus, were the FDA to address this question they would at variance with the Institute of Medicine, most physicians, the CDC, HHS and, oh yes, Michelle Obama.
May 30th, 2012
For several years the International Food Information Council Foundation (IFICF) has conducted a poll of American’s views on their health, diets, physical activity, and knowledge about foods. The results are always interesting. The new poll was conducted among 1,057 Americans, ages 18-80, in mid-April, 2012 and weighted to reflect the US population. Among its interesting findings:
Only 10% describe their health as ‘fair’ or ‘poor.’ This is a sharp drop from the pattern of the past 6 years in which just over 20% rated their health fair or poor. Conversely, those at “excellent” health shot up from the high-30% to 60%. Those rating their health as “good” dropped 10%. While the pattern of the survey has changed, the latest survey is more in line with CDC National Health Interview Survey data.
23% rate their diet as “very” or “extremely” healthful. 54% rate their diet as “somewhat healthful.”
87% of adults are trying to eat more fruits and vegetables, 78% cutting calories by drinking water, no calorie beverages. Women are more likely than men to be trying multiple strategies, as are those who are older and highly-educated.
Consumers who are obese, older and women are more likely to believe that changing nutritional guidance make it hard to know what to believe.
52% believe it is easier to do one’s taxes than to figure out how to eat healthy.
The proportion of American’s trying to lose weight increases with Body Mass Index (BMI). 32% of those with low to normal BMI are trying to lose weight, 57% of those who are overweight and 76% of those who are obese. 22% are trying to maintain their weight while 3% are trying to gain weight.
After a dip last year, the percent trying to lose weight has returned to historical norms…about 55%.
Only 1 in 7 Americans correctly estimate the number of calories needed to maintain their weight.
Only 3 in 10 correctly believe that all calories are equal; most believe sugars, carbs and fat calories are more likely to cause weight gain.
Two-thirds of moderately active Americans meet government recommendations for weekly activity duration. On average, adults are physically active 4.8 days a week for a median of 45 minutes. Half of physically active Americans engage in strength training. For the full report see 2012_IFIC_Foundation_Food_Health_Survey_Media_Resources
It is interesting that most Americans can rate the healthfulness of their own diet but find it confusing to figure out what healthy eating means. In part, this must be due to the cacophony of nutritional news/advice in the US media world. There is also a disconnect, called the healthy eating hypothesis, which posits that, if one eats healthy, normal weight level can be achieved or maintained. Yet, most studies show that while eating healthier foods is an overall improvement, its effects on weight are minimal. The fact is that our weight is determined by caloric intake/expenditure. Cutting out calories from broccoli is the same as cutting out calories from M & Ms. If you don’t believe me, see the advice from the prestigious Pennington Biomedical Research Institute website, Finding 100 calories. PBRC: finding-100-calories
May 29th, 2012
For the answers, see the new USDA ERS report and results from a randomized trial….More
May 29th, 2012
A common perception is that “healthy foods” are more expensive than less healthy foods. Researchers from the US Department of Agriculture Economic Research Service looked at three different ways to compare costs. One method was to look at the price per calorie, another to examine price per edible grams and the third, to look at the price per average portion size. They also looked at the price of meeting the Federal dietary recommendations for each food group.
Andrea Carlson and Elizabeth Frazao found that healthy foods were cheaper than less healthy foods, except for the price per calorie. Foods low in calories, like fruits and vegetables, appear to have a higher price when measured on a per calorie basis. When measured on the basis of edible weight or average portion size, grains, vegetables, fruit, and dairy foods are less expensive than most protein foods and foods high in saturated fat, added sugars, and/or sodium. USDA ERS: Are Healthy Foods Really More Expensive?
But what does this mean for your diet? If you consume the recommended amount of fruits and vegetables and other low calorie foods, you still need calories to meet your minimum daily intake requirements. So, if the “bad foods” are more expensive, that is a good reason to drop them from your diet? Well, yes if you want to save some money. But what if you are trying to lose weight? Earlier studies have suggested that reducing variety in non-nutrient dense, energy-dense food groups (think ice cream, potato chips, cookies, and candies) may result in lower overall energy intake and thus improve weight loss and weight management. The mechanism is thought to be ‘hedonics’, that the more boring the food is the less it is consumed.
In a clinical trial, Rena Wing and colleagues 200 adults were randomly assigned to either a lifestyle or lifestyle plus limited variety diet. Both groups received 48 group sessions over an 18-month period, covering cognitive behavioral intervention, a diet prescription, and a physical activity prescription.
The lifestyle + limited variety group was limited to 2 self-selected non-nutrient dense energy dense foods including baked goods, granola snack bars, high-fat crackers, frozen dairy-based deserts, frozen yogurt, ice cream, ice milk, cheese, candy, chips, salty snacks, and chocolate.
The results? Intake from this category was reduced, but overall energy was not and there was no difference in weight loss between the two groups. PubMed: Limiting Variety in non-nutrient-dense foods
May 29th, 2012
Two new studies expand our understanding of the influence of genetics on obesity…More
May 29th, 2012
Two new studies are shedding more light on the role of genetics in obesity. The first, from Lombard and colleagues at the University of the Witwatersrand in South Africa, looked at obesity in South African adolescents, and found 4 SNPs (single nucleotide polymorphisms) were individually significantly associated with body mass index (BM). Together, the four SNPs account for 2.1% of the variation in BMI. Each risk allele was associated with an estimated average increase of 2.5% in BMI. PubMed: Appetite regulation genes BMI association.
The second study, by Williams and colleagues at Uppsala University in Sweden, discovered 33 new genes associated with human obesity. The majority can be traced to distant species, such as D. melanogaster or the fruit fly and C. elegans, a roundworm. The authors speculate that these findings may identify new pathways for obesity drug development. PubMed: What model organisms and interactomics can reveal about genetics of human obesity
May 24th, 2012
That was the message from Rear Admiral (ret.) James A. Barnett, Jr. at a policy meeting May 23, 2011 in Washington, D.C.
Speaking for Mission: Readiness, a nonpartisan organization of over 300 senior retired military leaders, RAM Barrett called attention to the fact that, according to the Department of Defense, 75% of the 17 to 24 year olds in the United States cannot serve in the military, primarily because they are unfit, do not have a high school diploma or have a criminal record. 25% of young Americans are too overweight to join the military. Approximately 1,200 individuals are discharged from military service at the end of one year because they exceed the service’s weight standards. Barnett said that obesity was “eating away at our national security.” He indicated that the armed forces were taking steps to improve the food on military bases and in Department of Defense vending machines and snack food offerings. He also indicated that overweight soldiers were more subject to sprains and strains, necessitating their removal from combat operations.
Asked about the spouses of soldiers deployed overseas who reportedly experience significant weight gain, followed by drastic weight loss efforts when their spouses return home and if the Department of Defense had research on this population or programs for them, he said he wasn’t aware of any.
The event was sponsored by Weight Watchers International and arranged by the National Journal. David P. Kirchhoff, president of Weight Watchers Intl. said that he was optimistic that the message was finally getting through that obesity was about health, not appearance and that while there was not going to be a ‘silver bullet’ we had to bring “silver buckshot” to fight obesity. Mission: Readiness issued a 2010 Report, Too Fat to Fight. An update is in the works.
May 23rd, 2012
The influential Federal Agency for Health Care Quality and Research has issued a draft report “Approaches to Weight Management in Adults: A Comparative Effectiveness Review.” It is open for public comments. The deadline is June 20, 2012. AHRQ: Approaches to Weight Management in Adults