PERRY BUCHANAN: How dieting makes you fat

You may have seen news reports this previous year regarding contestants in “The Biggest Loser” regaining a significant amount of the weight they had lost during the reality TV show. New research explains why not only was the weight regained, but also explains how dieting may make you fatter!

To understand why the weight loss is not maintained, you must first have a fundamental understanding of metabolism and what contributes to the body’s total energy expenditure (TEE). There are three main factors that influence TEE.

1) Resting metabolic rate (RMR). RMR is the measurement of energy the body uses to maintain cellular homeostasis. Your RMR is responsible for 60 percent to 75 percent of your body’s TEE. Weight loss slows the body’s RMR through a process known as metabolic adaption or adaptive thermogenesis. With a slower metabolic rate, the body will more easily regain the lost weight.

2) Thermic effect of food. This is the energy used to digest, absorb, transport, metabolize and store what is eaten. It is about 10 percent of the TEE.

3) Physical activity induced energy expenditure. Physical activity can be divided in to two categories; exercise and non-exercise activity thermogenesis (NEAT). NEAT includes the calories expended outside of exercise, eating and sleeping. There are many NEAT activities that we already do, but may not realize its caloric output effect. Simple tasks such as yard work, physical labor, climbing stairs and even fidgeting help us expend additional calories. NEAT increases metabolic rate and results in a substantial energy cost over time.

The 2009 Biggest Loser contestants studied (14 total; 8 women and 6 men) were measured at three points. Just before the competition started, 30 weeks after the competition ended and 6 years after that. On average, the 14 contestants lost 128 pounds (24 lb. muscle and 104 lb. fat). They regained an average of 90 pounds (13 lb. of muscle and 77 lb. of fat). After 30 weeks, the average RMR had dropped by 611 calories and another 93 calories after 6 years. With a total average of 704 calories less being expended by RMR it could be said that dieting makes you fat.

As “The Biggest Loser” and other studies show, we can successfully develop weight loss programs through exercise, nutritional changes, and lifestyle modifications, but are a lot less able to prevent the regaining of lost weight. Restrictive diets may lead some people to become preoccupied with food, which triggers overeating. The suppression of metabolic rate and loss of lean mass may help lead to a post-diet weight rebound.

Not to be discouraged however, a 2005 National Weight Control Registry study shows it is possible to be a “successful loser”. The National Weight Control Registry (NWCR) is the largest ongoing study on long term weight loss. The NWCR was developed to identify and investigate the characteristics of individuals who have succeeded at long term weight loss. To be included in the study, one must have lost at least 30 pounds and kept the weight off for at least one year. On average, the 5,000 participants have lost 73 pounds and maintained the results for more than 5 years. Here are some key strategies found in that research study.

1) An hour of moderately intense exercise daily, such as brisk walking, was performed by 94 percent of registry participants. 62 percent of the participants watch less than 10 hours of TV per week.

2) 98 percent of Registry participants report they modified their food intake in some way. Most ate a low calorie/low fat balanced diet, including regularly eating breakfast and restricted periods of uncontrolled eating.

3) Frequently monitor weight and prevent small regains from becoming larger relapses. 75 percent of participants weigh themselves at least once a week.

4) Effectively manage depression and develop emotional regulation skills to control overeating.

Successful weight loss can be defined as losing 10 percent of body weight and keeping it off for at least 1 year. This is an effective standard since losing that much weight can bring meaningful reductions in health risk factors for heart disease and type 2 diabetes. To achieve and sustain results, follow the examples of successful losers who selected behaviors they could maintain for life. Try to avoid jumping impulsively on a fad program or quick-fix solution. Understand the differences of fact and fiction to live your fantasy of being a successful loser.

Perry Buchanan, owner of PT Gym, is certified as an Exercise Physiologist through the American College of Sports Medicine, and Fitness Nutrition Specialist through the National Academy of Sports Medicine. Email him at [email protected]. Follow @ptgym on Twitter.