DEAR DR. BLONZ: At the start of the new year, I made a commitment to lose weight. I have been down this frustrating road many times in the past, but the recent passing of a friend has provided new motivation. I have used a low-carb diet with some success, but my weight loss eventually slows down to a crawl. While eating almost nothing (compared to my usual diet), my weight becomes stable, and this drives me up the wall. I am hoping for some guidance. -- F.S., Oakland, California
DEAR F.S.: Continued frustration with weight loss often comes from a misunderstanding of exactly what happens when the body fails to receive the calories needed to maintain its weight. Pounds can drop quickly when people go on fasts, opt for drastic low-carbohydrate diets, or use regimens that include diuretic herbs. Excess body fat can be lost, but some of the loss can be water weight: a type that is quickly regained when the program ends. There can also be risks with these plans.
When you go on a diet, you create a situation in which insufficient calories are consumed to satisfy the body's demand. Because the body operates on a balanced energy "budget," it needs to borrow needed energy from its "bank account" -- stored body fat. In tandem with this, the body goes on a bit of a work slowdown, letting you know that it is not pleased. You know why you are consuming less food, but your body's survival systems are not in the loop. During weight-loss diets, the body becomes a raving miser, cutting out all unnecessary uses of energy to weather what it assumes is an ongoing famine.
The net effect of all this is a reduction of our basal metabolic rate (BMR), the energy used while the body is at rest. The reduction brings about a lowering of body temperature. A dieter may notice a greater tendency toward chills and fatigue, and perhaps a need for additional sleep. These are all normal adaptations as you deprive your system of the energy it needs and expects. But perhaps the main impact of a reduced BMR is that the number of calories needed every day drops, slowing the rate of weight loss.
Exercise can become an ally to reverse this trend. When you achieve and maintain a moderate activity level during a weight-loss program, your BMR will not drop as dramatically. As the level of exercise increases, you not only reduce the drop in BMR, you burn more stored fat. Exercise has even been shown to reduce the nagging hunger that often plagues the dieter.
Statistics show that a minority of Americans keep active on a regular basis. Clearly, though, for those who embark on a weight-loss plan, exercise can be the missing link to staying on track.
A consult with your physician is always an important first step, especially if there are ongoing health problems or risk factors involved with increased activity or dietary changes. Also, having a guidebook can help with inevitable bumps in the road. I recommend "A Small Guide to Losing Big" by registered dietitian Cheryl Forberg. This book covers many aspects of weight loss, from the perspective of a nutritionist who has worked on "The Biggest Loser" television show.
Send questions to: "On Nutrition," Ed Blonz, c/o Universal Uclick, 1130 Walnut St., Kansas City, MO, 64106. Send email inquiries to firstname.lastname@example.org. Due to the volume of mail, personal replies cannot be provided.