If you’re trying to lose weight – which will get you there faster – reducing calories and changing the quality of your diet or exercise? Of course, you should do both. Yet, it would be helpful to know what contribution each component adds to the equation. What does science say about this issue?
In a recent study, researchers reviewed 117 different studies (a meta-analysis) looking at the role diet and exercise play in weight and fat loss. What this study showed was both diet and exercise are important for losing weight. Yet making smarter dietary choices and watching portion sizes was linked with greater loss of body weight. On the other hand, exercise led to a greater loss of visceral fat.
What is visceral fat? It’s belly fat that lies deep in your pelvic cavity and wraps around internal organs, including the liver and pancreas. You’re probably most familiar with subcutaneous fat, the type you can pinch between your fingers. Subcutaneous fat may be what’s motivating you to lose weight but visceral fat is most important from a health standpoint because visceral fat is associated with chronic health problems, like type 2 diabetes, metabolic syndrome, and heart disease.
So, dieting impacts the number on the scale more than exercise but exercise attacks visceral fat, a type of fat that increases the risk of health problems. While losing weight and body fat may be your main motivation, zapping visceral fat is critical to your long-term health. Visceral fat is strongly linked with insulin resistance, a condition that places you at higher risk of health problems. So closely related are visceral fat and insulin resistance that a study published in Diabetes showed removing visceral fat prevents insulin resistance.
Unfortunately, visceral fat and insulin resistance both increase with age. We’ve almost come to accept the fact that waistlines grow wider with age, partially due to the accumulation of deep belly fat. Even worse is the fact that visceral fat secretes inflammatory hormones that partially fuel insulin resistance. Once insulin resistance sets in, it’s even harder to shed visceral body fat, being that insulin is a fat storage hormone. It’s a vicious cycle that’s hard to win – unless you exercise. Adding fuel to the metabolic fire of insulin resistance is the muscle loss that goes along with aging. Each decade after the age of 30, you lose between 3% and 5% of your muscle mass. In response, your metabolism slows. So, you’ve got a double whammy – increased body fat and decreased muscle tissue. No wonder our metabolisms slow and it’s so hard to take off body fat as we age!
Exercise and Body Composition
When you cut back on calories to lose weight, you lose a combination of body fat and muscle. When you glance at the scale, you might feel good about the number you see – but what about your body composition? According to one study, participants