You can choose from countless fad diets or fitness fads that are trending one minute and forgotten about the next. Most people know that both exercise and diet play a role in the overall weight loss picture, but which is a bigger driver? This question remains a topic of debate in the health and fitness community. Recently, that’s exactly what researchers wanted to find out.
Previous research has shown the benefits of long-term exercise in reducing adipose tissue and improving obesity, particularly through aerobic and higher-intensity exercise. You can also find plenty of research on how low-calorie diets, ketogenic diets, and other nutrition plans resulted in lower body fat. So, which plays the more significant role, what happens in the kitchen or the gym? Can you really outrun a bad diet? This new study weighs in.
Exercise or diet: Which matters more?

In a study published in PNAS, the researchers looked at 34 countries from around the world to compare the different cultures and the total calories burned every day. The study involved 4,213 adults of varying ages, including farmers and hunter-gatherer populations with lower obesity rates, as well as more sedentary people in areas like the U.S., where obesity is more prevalent. The researchers also used the United Nations Human Development Index (HDI).
The verdict

The researchers revealed that food choices are the main driver of obesity rather than being sedentary or a lack of exercise. They concluded the following:
- Interestingly, no matter the activity levels, the total daily calorie expenditure was similar across all populations studied.
- Despite people in these different countries having different physical activity levels, the amount of calories burned each day was consistent, suggesting that obesity is more strongly associated with an abundance of high-calorie foods in more industrialized nations.
Concluding thoughts

In more industrialized nations like the U.S., where there’s an abundance of readily available calorie-dense, processed foods, the rates of obesity grow along with it. It’s interesting to me that the total calories burned were similar across these populations and cultures, because we often hear that as societies become more developed and industrialized, they also become less active and burn fewer calories.
This study indicates that people from areas with higher rates of obesity burned only slightly less energy in the form of calories compared to populations with lower obesity rates. The researchers pointed out that the body adjusts to your lifestyle over time, adjusting how you expend energy.
Calorie-dense processed foods

The study showed that consuming processed, calorie-dense foods fuels obesity more than spending hours sitting at a desk and a lack of gym time, which aligns with previous research. That doesn’t mean that exercise doesn’t matter, and there’s plenty of evidence to back up the benefits for weight loss and beyond when you get your muscles moving. However, it seems you probably can’t outrun a bad diet after all, and nutrition is the bigger player in the weight loss picture.