WINNING THE WAR ON WEIGHT

Winning the War on Weight

ABSTRACT: Understanding the importance of exercise and the energy density of foods provides insight into lifestyle alterations necessary to lose weight.
CME OBJECTIVE: The reader will be prepared to recommend appropriate lifestyle modifications to achieve and maintain weight loss.
Douglas C. Heimburger, MD; C. Suzanne Henson, MS, RD; Jamy D. Ard, MD, no conflicts of interest.

Americans are fat and getting fatter, and obesity and overweight are among the major preventable causes of death in the United States. In 2000, poor diet and inactivity caused an estimated 365,000 deaths while tobacco use killed about 435,000 people, according to the Centers for Disease Control and Prevention.

Obesity is likely to kill even more people in the next decade: The National Health and Nutrition Examination Surveys show the percentage of overweight and obese adults increased from 55.9% in the years 1988 to 1994 to 64.5% in the years 1999 to 2000 (JAMA. 2002;288:1723-1727).

At any time in the US, 29% of men and 44% of women are trying to lose weight, but many of these attempts are unsuccessful, reports nutrition scientist Douglas C. Heimburger, MD, medical director of UAB's EatRight Program.

"Most people fail to achieve long-term weight loss because they lack support to make fundamental lifestyle changes," he says. "Eating patterns are such an integral part of individuals' daily routines that they are often not processed at the cognitive level. UAB's EatRight Program helps participants convert their diets into healthy eating patterns that can be maintained for a lifetime."

Causes of the US epidemic of overweight and obesity are multifactorial and complex, but Heimburger points to two key contributors — widespread availability and marketing of energy-dense foods and increasingly sedentary lifestyles.

Energy Density

"Understanding the energy density of food and eating lower-density meals is the cornerstone of the EatRight Program," Heimburger explains.

Energy density refers to the number of calories per unit of weight in a given food — the higher a food's water and fiber content, the lower its energy density. The EatRight Program places foods along a spectrum, with fruits and vegetables on the right and energy-dense foods high in sugars and fats on the left. Participants are encouraged to "eat to the right" of the scale.

"The total weight of food consumed affects satiety. People tend to eat the same weight of food, regardless of calorie content," says C. Suzanne Henson, MS, RD, EatRight Program coordinator. Studies show when given high-density and low-density food choices on different days, participants ate similar-sized portions but consumed one third fewer calories when eating low-density foods (Am J Clin Nutr. 2001;73:1010-1018).

"Many people try to lose weight by replacing a high-fat, high-density food with another high-density food that happens to be low in fat. Pretzels are a good example," Heimburger says. "Pretzels' low-fat content makes them seem like a good snack option, but they contain almost no water, so people can eat large amounts without feeling full and may consume the same, or more, calories."

EatRight helps participants reduce the energy density of their diet by showing them how to adapt individual dietary preferences to include more low-density foods. "These foods provide a lot of fiber and bulk for the number of calories consumed, and people do not feel hungry," he says.

"Often, EatRight participants are surprised by the amount of food we ask them to eat. It is often a greater volume than they were previously eating, but they lose weight because total caloric intake is lower," Henson says.

During the 12-week EatRight Program, participants lose an average of 5% of their body weight, or 8 to 25 pounds, says UAB nutrition scientist Jamy D. Ard, MD, EatRight associate medical director. "Follow-up studies of EatRight participants show 5 years after completing the program, about 50% maintain their weight loss and 70% remain below their baseline weight," he says.

Barriers to Exercise

Physical activity is an indispensable component of any weight-loss program, Heimburger says. "When discussing exercise strategies with patients, physicians need to help them set realistic goals and overcome barriers to exercise. For example, many patients cannot afford health clubs, some live in neighborhoods unsuitable for walking, and others have trouble fitting workouts into busy schedules.

"Physicians should encourage sedentary patients to start small," he continues. For these individuals, adding any activity, such as climbing stairs instead of taking the elevator, is a good first step. Physicians also should be aware of community resources, including area fitness trails, shopping malls with space for walkers, and low-cost exercise programs."

"The EatRight Program sets patients up for success by asking them to meet one achievable goal each week," Henson says. "That success keeps them motivated and helps them continue making positive incremental changes in their lifestyles. As patients make changes and feel more confident, goals can be reevaluated and revised upward."

Choosing the Optimal Diet

Last year, Americans spent more than $40 billion on health clubs, diet books and videos, diet sodas and artificial sweeteners, and weight-loss centers and liquid diets, Ard says.

Consumers are faced with a bewildering array of diets; the Atkins diet, the Zone Diet, and the South Beach Diet all sell patients on the promise of rapid results. "These diets work in the short term because they decrease caloric intake, and initial weight loss encourages adherence," he says. "Yet, patients need to be reminded they did not gain excess weight quickly and permanent weight loss takes time and effort."

A recent New England Journal of Medicine study (2003;348:2082-2090) randomly assigned 63 obese men and women to either low-carbohydrate, high-protein, high-fat diets or to conventional diets (low-fat, low-calorie, high-carbohydrate). At 6 months, patients on the low-carbohydrate diet achieved greater weight loss, but differences between the two groups were not significant at 1-year follow up.

"Although low-carbohydrate diets work for many people in the short term, there are concerns about overall safety and healthfulness," Ard says. "Eliminating fruits, vegetables, and dairy decreases fiber and calcium intake and there is concern that substituting higher intakes of fat and animal protein for carbohydrate increases risks for gout, renal disease, breast and prostate cancer, and heart disease."

Management Strategies

"Physicians should begin by explaining to patients that obesity is a chronic disease that increases the risk of many conditions, including cancer, liver disease, type 2 diabetes, osteoarthritis, hypertension, stroke, and heart disease," Ard says.

Reductions of just 5% of total body weight can reduce disease risk and decrease the need for medications. Describing these benefits to patients and asking them to monitor their eating habits are simple yet powerful tools. Helping patients pinpoint stimuli that lead to over-eating can promote positive change.

Once realistic initial weight-management goals are set, Ard advises physicians to follow up on patients' efforts to encourage adherence and success.

"The EatRight Program stresses that patients' weights after 12 weeks are less important than where they are after 2 years or 5 years," Heimburger concludes. "Asking them about long-term goals informs their current decisions and helps put their weight and health issues in perspective."

For more information:
Dr. Doug Heimburger
Dr. Jamy Ard
Suzanne Henson
1-800-UAB-MIST
mist@uabmc.edu