Exercise can be a powerful balm for many of the things that ail us, including depression, bone loss, fatigue, heart disease, diabetes and arthritis. But if a goal of exercise is to lose weight, you’ll increase your chances of success by changing your diet.
Modifying your diet – specifically controlling your portions – makes a bigger difference for weight loss than exercise alone, research shows. In a 2012 study comparing diet and exercise for weight loss, postmenopausal women who changed their diet alone lost an average of 7.2 kilograms (almost 16 pounds) over the course of the 12-month study, while those in the exercise only group lost just 2 kg (just under 4 ½ pounds).
The reason boils down to simple math. It is far easier to not eat 100 than it is to burn them off, which, for most of us, would require walking one mile.
Experts from the American College of Sports Medicine and the American Heart Association reviewed all available scientific evidence on the connections between exercise and health and wrote in 2007: “Despite the intuitive appeal of the idea that physical activity helps in losing weight, it appears to produce only modest increments of weight loss beyond those achieved by dietary measures and its effects no doubt vary among people.”
Amy Luke, PhD, a nutritional epidemiologist at Loyola University, Stritch School of Medicine, in Chicago, has seen this phenomenon for herself.
Luke compared two populations of black women: One group was from rural Nigeria, while the other was from downtown Chicago. All body size measurements were lower in the Nigerian women, and Luke and her team set out to understand why.
“Our hypothesis going in was not particularly brilliant,” Luke says. “It was that women who were heavier, particularly in the U.S., would have lower calorie expenditure than women who had a lower body mass index (BMI).” In other words, she thought thin women would be more physically active than obese women. That turned out not to be the case. “The differences in physical activity were minimal,” Luke says.
Luke believes the Chicago women weigh more than their Nigerian counterparts because of differences in diet. The Chicago diet is 40–45% fat and high in processed foods, while the Nigerian diet is high in fiber and carbohydrates, and low in fat and animal protein.
“For us, the take-home message is that a lot of public health policy on increasing physical activity for weight control may not be as productive as focusing on the dietary intake side of things,” says Luke, whose study was published in the journal Obesity.
Diet and Exercise Together for Success
Most experts agree that an effective weight loss plan requires both a reduction in calories and increase in physical activity. In the study of postmenopausal women, which was published in the journal Obesity, the greatest weight loss was for a group that combined exercise with diet – for an average loss of 8.9 kg (almost 20 pounds).
In the National Weight Control Registry, a group of 5,000 individuals who have lost at least 30 pounds and kept it off for at least one year, 98% of people enrolled modify their food intake and 94% increase their physical activity.
The trick, experts say, is to carefully monitor how much you’re eating by counting calories, watching portion sizes, keeping a food journal or using a phone app that tracks food consumption, while increasing your physical activity. Although your greatest weapon against obesity is diet, exercise can boost the weight-loss benefits of diet while providing the additional benefits of relieving joint pain, fatigue, boosting mood and helping to keep your heart and bones strong.
- Benefits of Weight Loss
- Arthritis & Obesity
- Which Arthritis Diet Plan Should You Try?
- Add These Arthritis-Friendly Foods to Your Diet
- How Exercise Helps Your Joints