Weight Loss: A Matter of Life and Death (December 3, 2007) By Jeremy Appleton, ND

Fighting the battle of the bulge is more important than ever, and may have gotten a little easier, judging from a series of articles recently published in Archives of Internal Medicine.

The articles, which addressed several different issues relating to the health consequences and treatment of obesity, collectively suggest that weight loss should be a high priority for a large number of Americans. The articles also suggest that lasting weight loss can be achieved through simple diet changes and exercise.

The Risks of Obesity

About one-third of the U.S. population is overweight.1 Excess body weight?and, in particular, male pattern obesity characterized by excess abdominal fat as opposed to fat accumulation in the thighs and buttocks?is implicated as a risk factor for many different diseases. The best-documented risks associated with obesity include cardiovascular diseases (e.g., coronary heart disease, hypertension)2 and type 2 diabetes.

However, obesity appears to increase the risk of many other conditions as well, including prostate enlargement (called benign prostatic hyperplasia, or BPH),5 gallstones,6 certain cancers (e.g., breast cancer in postmenopausal women, uterus, colon, and kidney),7 female infertility,8 uterine fibroids,9 work disability,10 and overall mortality.11 The risk of death from cardiovascular disease, cancer, or other diseases increases in overweight men and women in all age groups.12 A four-year study of over 40,000 women found that weight loss in overweight women was associated with improved physical function and vitality as well as decreased bodily pain.13

How Fat is Fat?

A variety of physical measurements have been used to quantify a person?s risk of obesity-related diseases. These include the body mass index (a marker of general obesity), waist circumference, and waist-hip ratio (both markers of abdominal obesity). The body mass index (BMI) is calculated by dividing your body weight (in kilograms) by the square of your height (in meters). The standard for normal body mass has been set by the World Health Organization (WHO). In 1997, a WHO report defined ?overweight? as a BMI of 25 to 29.9 for men and women ages 19 to 69, with certain exclusions. Individuals with a BMI of 30 or more are considered ?obese? and those with a BMI of 40 or greater are considered ?severely obese.? These criteria supercede a previous standard, by which women were overweight at BMI 27 and men at BMI 28.

The waist-hip ratio (WHR) is calculated by dividing your waist measurement by your hip measurement. The waist is measured at the narrowest point of the relaxed abdomen. The hips are measured at their widest place. A WHR ratio of 1.0 or greater for men and 0.8 or greater for women indicates that fat stores are carried around the middle, and this is believed to increase the risk for diabetes, heart disease, and hypertension. BMI and WHR calculators are widely available over the Internet.

A new study, published in the July 24 issue of Archives of Internal Medicine, found that BMI and waist circumference effectively identify older women at risk of diabetes, hypertension, and cardiovascular disease.14 This study also found that the WHR further identifies women at increased risk of death and several serious illnesses, including coronary heart disease, other cardiovascular diseases, and cancer.

Who Needs A Weight-Loss Program?

Criteria for determining who needs a weight-loss program were recently developed by the National Heart, Lung and Blood Institute?s Obesity Education Initiative Expert Panel.15 16 These criteria consist of a combined interpretation of the BMI, waist circumference, and presence of other cardiovascular risk factors.

However, despite the importance of abdominal obesity as a risk factor for cardiovascular disease,17 18 19 20 measuring waist circumference as recommended by the panel may not provide useful information. Waist circumference measurements do not appear to improve cardiovascular risk screening beyond what is offered by the BMI and conventional cardiovascular risk factors, such as serum cholesterol, blood pressure, and cigarette smoking. New research, published in the July 24 issue of Archives of Internal Medicine, shows that the panel?s proposed screening technique fails to identify a substantial percentage of at-risk overweight women and men.

The study?s findings highlight the need for tailored weight-loss interventions. The authors of the study, Michaela Kiernan, PhD, and Marilyn A. Winkleby, PhD, of the Stanford Center for Research in Disease Prevention, used a simpler combination of BMI and cardiovascular risk factors to identify adults in need of weight-loss treatments. By their calculations, the percentage of adults needing weight-loss treatment is ?staggering,? particularly among those with lower educational attainment.

Among those without a high school degree, more than 57% of black women and more than 45% of Mexican-American women were identified as needing weight-loss treatment. According to another recent report,22 however, 58% of obese patients (BMI greater than or equal to 30) are not advised by their healthcare provider to lose weight. Socioeconomic factors appear to influence the likelihood of being advised to lose weight. Unfortunately, many weight-loss programs are targeted at white, well-educated women who, according to Kiernan and Winkleby?s study, are the group of women least likely to actually need weight-loss treatments.

Take-Out Meals: Blessing or Curse?

Consumer spending for take-out meals now exceeds $100 billion per year, according to AC Nielsen, a leader in market research. Nearly one-fourth of U.S. food dollars are used to purchase take-home meals, according to the agency. The rapid growth of home-meal replacement (HMR) has ramifications not only for food retailers, but for healthcare providers and consumers, as well.

Home-meal replacement is a double-edged sword. Many fast-food outlets sell artery-clogging, calorie-rich foods with questionable nutritive value, yet there is a growing trend among HMR providers to deliver meals that are more healthful. While the meals provided by natural-foods markets and other health-conscious companies have not been proven to promote weight loss, a new study from the July 24 Archives of Internal Medicine suggests that such benefits are possible.

A one-year clinical trial carried out at five university-based medical centers has shown that a nutrient-fortified prepared-meal plan is a more effective weight-loss tool than a nutrient-equivalent ?usual-care diet? in which participants prepared their own meals based upon lists of approved foods.23 Among overweight and obese participants, those consuming the pre-packaged, nutritionally balanced meals lost significantly more weight that those receiving food-preparation counseling and compensation for food purchases. Moreover, cardiovascular risk factors (e.g., blood pressure, cholesterol levels, and blood sugar) were reduced, and overall quality of life was improved to a greater degree in those receiving the prepared-meal plan than among those consuming the usual-care diet. Not surprisingly, compliance with the recommended diet was higher in the group receiving prepared meals.

Walk and Keep It Off

For many people, losing weight is easier than keeping it off. Maintenance of weight loss is perhaps the most difficult challenge in the treatment of obesity. Although studies have shown that exercise alone (without dietary restriction) can promote weight loss in obese individuals,24 exercise can also be used to enhance the effectiveness of dietary weight-loss regimens. A study of overweight women found that engaging in an exercise program helped them adhere to a low-calorie diet.

New evidence suggests that the amount of exercise needed to keep the fat off after a weight-loss program is actually minimal.26 Eighty-two premenopausal women took part in a 12-week weight-loss program, followed by a 40-week maintenance program randomized in three groups: Group 1 received dietary counseling but did not increase their exercise; Group 2 received dietary counseling and increased their walking to 2?3 hours per week; Group 3 received dietary counseling and increased walking to 4?6 hours per week. Two years after the beginning of the trial, body weight, fat mass, and waist circumference were measured in all participants.

Compared with the end of the weight-reduction period, weight regain at the two-year follow-up was 3.5 kg (7.7 pounds) less and waist circumference was 3.8 cm (1.5 inches) less in Group 2 (walking 2?3 hours per week) compared to Group 1 (no walking). The unique finding of this trial was that the favorable effects were only observed in those women walking a moderate amount. In contrast, women in Group 3, with a higher exercise target of 4?6 hours per week, did not maintain their weight, body fat, or waist circumference any better than did Group 1, which received only dietary counseling.

The results of these trials highlight that simple measures, such as opting for healthier take-out food and walking for two to three hours per week, can significantly contribute to an effective weight-loss program.

Source:

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Jeremy Appleton, ND, is a licensed naturopathic physician, writer, and educator in the field of evidence-based complementary and alternative medicine. Dr. Appleton is Chair of Nutrition at the National College of Naturopathic Medicine and Senior Science Editor at Healthnotes.