Weight loss through calories reduction or exercise are generally good for most people as an intervention in obesity, although the appropriateness of these methods has historically been a matter of controversy in older, obese adults.
A major concern with weight loss is the accompanying loss of lean tissue, which can accelerate existing sarcopenia (age-related loss of muscle and strength), and result in reduction of bone mineral density that could worsen frailty. This could lead to greater risk of bone fractures and broken hips. Studies have yet to provide sufficient evidence, one way or another, as to whether or not weight loss provides a true enhancement to quality of life.
In a one-year, randomized, controlled trial, researchers from Washington University School of Medicine in St. Louis evaluated independent and combined effects of weight loss and exercise in nearly 100 obese older adults with an average age of 70.
The study, published their findings in the March issue of New England Journal of Medicine, randomized subjects into one of four groups:
1. Control group – participants of which did not receive any advice to change diet or activity.
2. Diet group – prescribed a diet with a deficit of 500 to 750 Calories per day and containing 1 gram of high-quality protein per kilogram of body weight per day 3. Exercise group – prescribed a diet to maintain weight while participating in three group exercise trainings weekly, which included 90 minutes of aerobic exercises, resistance trainings, and flexibility and balance exercises.
4. Diet-exercise group – prescribed a combination of the weight management instructions and exercise trainings as described in 1 and 2.
To "even the playing field" and reduce confounding variables of vitamin D and calcium status, the researchers gave all participants supplements: approximately 1500 milligrams of calcium and 1000 IU of vitamin D per day.
Results from this carefully designed study show the "diet-exercise group" preserved more lean muscle and bone density when compared to the other groups. They gained significantly better physical function and were less frail than other groups and outperformed other groups in all measured parameters: Physical Performance Test (PPT), peak oxygen consumption (VO2pseak), and Functional Status Questionnaire (FSQ) (see graphs).
"Weight loss combined with regular exercise may be beneficial in helping obese older adults maintain their functional independence," the authors concluded.
Generally, most older, obese adults are able to safely engage in regular physical activity; however, a medical professional can determine which exercises are appropriate for an individual's specific needs. Because fitness levels vary, it's important to consult a physician prior to beginning any exercise program. Certain medical conditions, as well as medications, can also affect a person’s tolerance for exercise.
Engaging in a variety of exercises, such as aerobic exercises, resistance training, and flexibility exercises, can lead to optimal health benefits. Each is essential for healthy aging.
Aerobic Exercise
Aerobic exercise of moderate intensity, 30 minutes a day, five times per week is currently recommended for adults ages 65 and older, according to the guidelines presented by the American College Sports of Medicine (ACSM). Those who are not used to exercising can start out with a shorter duration at a lower intensity and work their way up to the recommendations.
Aerobic exercise can lead to improved cardiovascular function, better quality of sleep, improved mental health, weight loss and enhanced immune function. Suggested aerobic activities for older adults include low-impact exercises such as walking, biking, low-impact aerobics, and water activities such as swimming or water aerobics.
Resistance Training
Resistance training is essential to preserve lean muscle and bone density or even reverse previous losses. In addition to improving physical function, resistance-based exercises can also reduce risk of some medical conditions like diabetes and hypertension.
Older, obese adults should perform resistance-training exercises two times weekly. The trainings should consist of 8 to 10 different strength exercises with 8 to 12 repetitions each. Again, it's best to start out slow, with lighter weights and fewer repetitions.
There are many different types of strength training exercises and a variety of equipment that can be used, including: weight-training machines, dumbbells, resistance bands, medicine balls, weighted bars, resistance of water or even one’s own body weight.
For optimal benefits, it is best to work muscles to the point of fatigue, without overstraining, while taking enough time between workouts to allow the muscles to rest and recover.
Flexibility Exercises
Flexibility and balance are also factors important to health that decrease with age. Leading a sedentary lifestyle can cause connective tissues to weaken and joints to stiffen. Ultimately, the lack of activity affects a person's range of motion, balance and posture.
Performing stretching exercises regularly can help improve flexibility and increase freedom of movement. Every workout should begin and end with proper stretching exercises to help warm up and soothe the muscles. Stretching, along with strength exercises, can also improve balance, which can help reduce the risk of falling – particularly important for elderly individuals.
Final Word
It's never too late to begin a weight-control and exercise program. Along with a healthy diet, engaging in individually-appropriate physical activity—aerobics, resistance training, and flexibility exercises—can provide older adults with improved physical function and a variety of health benefits.
Reference
Villareal DT, Chode S, Parimi N et al. Weight loss, exercise, or both and physical function in obese older adults. N Engl J Med 2011;364:1218-29.
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