Diligently Walking but Not Losing Weight? You're Not Alone

An international study led by Loyola University in Chicago provides new evidence that exercise is not the key to weight loss.

Researchers examined young adults from the United States and four other countries, discovering no connection between the time spent on physical activity and their weight. "The study found that engaging in sports doesn't protect us from weight gain," says lead researcher Dr. Lara R. Dugas.

Exercising unquestionably offers many health benefits, including lowering the risk of heart disease, diabetes, and cancer, as well as improving mental health and mood. People who exercise regularly tend to be healthier and live longer. But if you're jogging regularly to lose weight, you're likely to be disappointed. The researchers note that while exercise burns calories, it also increases appetite, and people often "compensate" for morning workouts by being inactive for the rest of the day.

Until recently, an assumption among experts was that today's sedentary lifestyle, with minimal physical activity, is a leading contributor to the global obesity epidemic. However, new research, like the current study by Loyola University, contradicts this assumption.

The study of physical activity was part of an international program tracking people aged 25 to 40 across five countries: the United States, Ghana, South Africa, Jamaica, and Seychelles. Participants came from all socio-economic backgrounds.

Previous research has shown that when people self-report their physical activity, they tend to exaggerate. To achieve a more objective measure, Loyola participants wore watch-like tracking devices for a week. These devices measured their energy expenditure and daily steps. Researchers also measured each participant's weight, height, and body fat percentage. After the initial assessment, participants were re-examined after one year and again after two years.

Initially, it was found that Ghanaian citizens were, on average, the slimmest (men and women averaged 63 kilograms), while Americans were the heaviest (women averaged 91.6 kilos, men 93.4 kilos). 76% of Ghanaian men and 44% of Ghanaian women adhered to the American Health Ministry's physical activity guidelines, whereas only 44% of American men and 20% of American women met these recommendations. The American Health Ministry recommends two and a half hours of moderate-intensity aerobic activity (such as brisk walking) weekly.

In follow-up assessments, no link was found between regular physical activity and weight loss. The only factors linked to weight gain were initial body weight (meaning participants who weighed the most at the start of the study gained the most weight), age, and gender.

Of course, the study didn't examine the effects of an especially intensive workout plan. If you're working out vigorously for two hours a day at the gym, this study's results may not apply to you. However, when it comes to more average physical activity—a daily half-hour walk or a few weekly aerobic classes—it's simply unreasonable to expect these to change your weight. Physical activity is good for health—but a person's weight is primarily influenced by diet.