Too many fat bellied children

A study from the University of Rochester Medical Center has found that abdominal obesity increased more than 65 percent among U.S. children between 1988 and 2004. This finding is significant because abdominal obesity has emerged as a better predictor of cardiovascular disease and type 2 diabetes risk than the more commonly used Body Mass Index (BMI), a weight to height ratio that can sometimes be misleading.

As the first nationally representative study to document the increase in children’s belly fat, the study published in the journal ‘Pediatrics’ paints a bleak picture for these children who have a higher risk of heart disease, adult-onset diabetes and metabolic syndrome.

Increases in BMI scores have been raising concerns about the short and long term health of children throughout the developed World, but the increase in the rates of abdominal obesity in children appears to have been even more pronounced. According to data from the National Health and Nutrition Examination Survey between 1999 and 2004, the percentage of 6 to 11 year old children with high BMI scores rose about 25 percent. But the increase in abdominal obesity of the same group over the same period was more than 35 percent.

The good news is that, for children and adolescents, the health effects are often reversible through improved lifestyle for weight loss. Study author Stephen Cook, M.D., an Assistant Professor of Pediatrics at the University of Rochester, said that the study should be a warning for physicians and parents to limit sedentary activities, such as TV and computer time, and to teach and model healthy eating and exercise behaviors.

“Kids, teens and adults who have early stages of atherosclerosis in their arteries can have a healthy cardiovascular system again,” said Assistant Professor Cook. “Older adults who have plaque build up have a much harder battle, especially if the plaque has calcified.”

Measuring waist circumference is not a “vital sign” normally taken in a visit to the doctor. A BMI is commonly calculated, but there are limitations to those measurements. A very muscular person may register a high BMI score, even if s/he is very healthy and has an average waist circumference. Whereas, a sedentary child may not register a very high BMI score even though they are carrying a lot of fat around their abdomen putting them at a higher risk for health problems.

China’s growing waistline

About 20% of the more than 1 billion overweight people in the World are Chinese. China is often overlooked when discussing the obesity crisis that is sweeping the developed World because the prevalence of overweight and obesity in China is relatively low at 15% when compared with countries such as the United States where over half of the population are overweight. An article in the British Medial Journal by Professor Yangfeng Wu from the Chinese Academy of Medical Sciences has suggested two key reasons why we should be taking more notice of this looming crisis in China.
Professor Wu points out that there has been an alarmingly rapid increase in overweight and obesity in China in recent years, especially in school children for whom prevalence of overweight increased 28 times between 1985 and 2000.
Professor Wu also points out that there is increasing evidence that the World Health Organization’s definition of overweight and obesity, which is derived from studies on the correlations between Body Mass Index (BMI) and disease in white populations, may not be applicable to Asian populations. The Working Group on Obesity in China has recommended that lower BMI cut points should be used to determine overweight and obesity in China. If these cut points were used then over a quarter of a billion people in China would be regarded as overweight or obese.
The explanations for China’s recent epidemic of overweight and obesity are the same as for the rest of the World. Poor diet and reduced levels of physical activity due to the continuing modernization of transport and labor activities. China has the added problems of a widespread belief that excess body fat represents health and prosperity and that it has become difficult to find safe places in over crowded residential areas to exercise or even walk.
Professor Wu said that China needs to act now if it is to have any chance of preventing a further increase in obesity rates. He suggested that as a first step, the prevention and control of obesity should be listed in China’s framework and policy on health. He hopes that by acting now China may be able to achieve where the West has so far failed in halting the growing obesity problem.

BMI Unreliable

Two recent studies have questioned the use of the Body Mass Index (BMI). A study published in the American Journal of Clinical Nutrition has found that the BMI based risk categories overestimate the risks associated with excess weight in people aged over 75. A second study Published in The Lancet found that cardiac patients classified as Overweight (25-29.9) using the BMI had lower risk of death than patients classified as Normal weight (20-24.9) or Underweight (<20).

The BMI, which is calculated as weight (kg) divided by the square of height (m), is an easily measured indicator of obesity and is used by most expert bodies such as the National Institutes of Health and the World Health Organisation.

The studies revealed that those with a low BMI were at the highest risk of death. According to the studies’ authors, an explanation for the lack of positive association with BMI and mortality at older ages is that BMI is a poor measure of abdominal fat, the key determinant of metabolic abnormalities that contribute to cardiovascular risk. The BMI does not differentiate between fat and fat-free mass so as older people lose muscle with age their BMI drops making them appear healthier. There can be substantial differences in percentage of fat and lean body mass between individuals whose BMIs are the same.

The better outcomes in overweight and mildly obese people may be because these people have a greater lean ‘muscle’ mass than normal weight and severely obese people. Lean muscle mass is important because it is metabolically active tissue, meaning that it burns energy, so the more muscle mass you have the higher your metabolism and the more fat you burn. Greater muscle mass may also indicate increased physical activity, which independently contributes to reduced coronary artery disease.

Waist circumference, which has been proposed as an alternate measure of obesity, was found to have no association with mortality. “A limitation of waist circumference alone as a measure is that it takes no account of body composition, whereas waist hip ratio is a measure of body shape and to some extent lower trunk adiposity [abdominal fat]“, said the one of the studies’ authors.

The first study found the Waist Hip Ratio (WHR) to be a better indicator of mortality risk in older people. The authors concluded that WHR should be used for people over the age of 75 because of its positive association with risk of death and that particular attention should be paid to the problem of muscle loss in old age.

Parents Influence Obesity

The amount and quality of time parents spend with their children has a direct effect on children’s rates of obesity, according to a new study from Texas A&M University.

The five year study found that the more time a mother spends with her child, the less likely that child is to be obese, however fathers were found to be a bad influence on their child’s obesity. “For a long time we thought that parents ought to influence what their kids eat, but we were not sure how that worked.” Lead researcher Professor Alex McIntosh said.

Because so many families are headed by two working parents, the focus of the research was to look at how the parents’ work-related stress, flexibility and general work conditions influenced the children’s nutrition, McIntosh said.

The study found that the fathers of 9 to 11-year-olds’ spend an average of 80 minutes per day with their children, while mothers’ average time spent with their children is 125 minutes. Children ages 13-15 included in the study saw their fathers an average of 95 minutes per day, while mothers of this age group spent an average 87 minutes per day with their children.

Income levels for the mother and father were also evaluated, examining the effects on a child’s nutritional intake. Professor George Davis from the department of agricultural economics at Texas A&M, said as parents’ income goes up, their children’s body mass index also increases. His advice to parents: “You’re not at work 24 hours a day. For mothers: For the time you do have, spend some with your kids. For fathers: Dads are not toxic, but people who teach nutrition education may be talking to the wrong audience. Men in general tend to have more muscles and less fat than women do, and consequently can eat more food without gaining weight. That means they may not be paying as much attention to nutrition as women do. “We may need to teach fathers about nutrition,” McIntosh said.

 

Rationalizing obesity

A new study has found that more than four out of five Americans characterized their eating habits as healthy. This is despite the fact that 65% of American adults are overweight and over 30% are obese. The study conducted by Thomson Medstat involved a telephone survey of 12,000 American adults as part of the 2006 PULSE survey, America’s largest ongoing, privately sponsored consumer health survey. The findings of the survey suggest that for most people obesity is the result of occasional indulgence in a number of risky behaviors.

In addition to the specific eating and lifestyle habit questions, respondents were asked for their heights and weights. Results were then categorized by respondents’ body mass index (BMI) to determine trends among underweight, normal weight, overweight, obese and morbidly obese people.

When respondents were asked how often they consumed fast foods, ‘upsized’ their fast foods and ate unhealthy snacks there were small differences between normal weight and overweight people. However, over half of the respondents said they did not exercise for 20 minutes more than two times per week.

One result that was very clear was the relationship between respondents who reported that they had diabetes and BMI. Five percent of the normal weight respondents reported having diabetes. This rose to 9% for overweight respondents, 19% for obese respondents and a staggering 34% for morbidly obese respondents.

The conclusion is that while very few people from any of the BMI categories consistently ate super sized fast foods, snacked recklessly or even characterized their eating habits as poor, several high risk behaviors have combined to become part of the average American’s weekly routine. Through a combination of occasional fast foods, moderate snacking, not quite enough exercise and the belief that these habits are ’somewhat healthy’, Americans are rationalizing themselves into ever-expanding waistlines and diabetes.

Calcium Affects Weight

Increased total calcium intake in the form of supplements can help middle-aged adults maintain their weight over a number of years, with particular benefits to women, according to researchers at the Fred Hutchinson Cancer Research Center in Seattle.

The study looked at relationships between calcium and weight change over an eight-to-12-year period among more than 10,000 men and women in their mid-50s. Previous studies have found connections between calcium intake and people’s body mass index, but those studies focused on calcium in food, not supplements, according to the researchers.

The study examined people’s intakes of dietary calcium, supplemental calcium and total calcium (supplements plus diet) to discover which forms of calcium were associated with weight change. The researchers found “dietary calcium alone had no significant effect on 10-year weight change,” but that women who took calcium supplements saw some improvement.

“Although more evidence from randomized clinical trials is needed before calcium supplements can be recommended specifically for weight loss, this study suggests that calcium supplements taken for other reasons (e.g., prevention of osteoporosis) may have a small beneficial influence on reducing weight gain, particularly among women approaching midlife.”

From the American Dietetic Association