Rosanne Leipzig, MD, PhD, is Professor and Vice Chair of the Brookdale Department of Geriatrics and Adult Development at the Icahn School of Medicine at Mt. Sinai in New York, N.Y. She also serves as Editor-in-Chief of the monthly publication Mount Sinai School of Medicine Focus on Healthy Aging.

Dr. Rosanne Leipzig, Professor and Vice Chair of the Brookdale Department of Geriatrics and Adult Development at the Icahn School of Medicine at Mt. Sinai in New York, N.Y., addresses reader questions on weight loss.

Q: A friend thinks focusing on diet is enough to lose weight, but I say you need to combine diet and exercise—which of us is right?

A: Portion-control can help you lose weight by reducing your calorie intake, and exercise does so by helping you burn off calories. But both approaches are effective when used separately—you don’t necessarily need to combine them. However, you might see swifter results if you do, and combining them also may help you maintain a healthy weight ongoing.

I recommend replacing refined grains (such as white pasta and rice, and baked goods made from white flour) with whole-wheat bread and pasta, and brown rice. These unrefined grains are low in calories, and fiber-rich—and because fiber takes longer to digest you feel fuller for longer after eating it, and may be less likely to go for high-calorie snacks between meals. Also increase your consumption of fruits and vegetables. Boosting your protein intake can help too—it’s difficult to digest, so the body exerts more energy metabolizing it. In fact, one of the best ways to start the day in fat-burning mode is to include protein as part of your breakfast.

As far as exercise goes, aim to build up to (and preferably exceed) the target 150 minutes per week of moderate-intensity aerobic activity recommended by the Centers for Disease Control and Prevention (CDC). Also engage in strength training on two or more days per week. For more on the Federal exercise guidelines for seniors, visit the CDC website’s page on Physical Activity. If you have any health issues, check with your doctor whether it’s safe for you to exercise—and if you’ve been sedentary up to now, start slow and gradually increase the amount and intensity of your physical activity.

Q: I’ve seen a number of ads saying I should “cleanse” my insides, and that doing so will help me lose weight. What are your views?

A: The idea behind “detoxification” diets is that chemicals, pollutants, and other toxins from the environment build up in your body over time. Proponents of cleansing diets say that if you consume only juice, fruit, or water for a few days, you can clear out all of these toxins. Some cleansing diets also add herbal laxatives, diuretics, or colonics to help you “flush out” your system.

Although the claims may sound enticing, the scientific evidence to suggest that detoxification diets actually work is virtually nonexistent. By limiting your diet so strictly, you may be depriving your body of essential nutrients—you also may be risking side effects if you are on any medications that are supposed to be taken with food. Taking laxatives or diuretics without your doctor’s knowledge also can be dangerous.

Both diuretics and laxatives can cause fluid, electrolyte, and mineral imbalances (e.g., potassium, phosphorous, and magnesium) resulting in dehydration, arrhythmias (heart disturbances), and weakened muscles. As for the promised weight loss, you’ll put the pounds right back on as soon as you get off the diet. If you really feel you need to lose weight, aim for a steady reduction of one to two pounds per week, which you can best achieve through portion control and more physical activity.

(Ed. Note: For related reading, see these University Health News posts:

Rosanne Leipzig, MD, PhD, is Professor and Vice Chair of the Brookdale Department of Geriatrics and Adult Development at the Icahn School of Medicine at Mt. Sinai in New York, N.Y. She also serves as Editor-in-Chief of the monthly publication Mount Sinai School of Medicine Focus on Healthy Aging. Visit her personal website at www.rosannemd.com.