You’ve probably heard that “you can’t out-exercise a bad diet.”
While this saying has some merit, you may wonder whether diet or exercise is more important for health goals like weight loss or improved heart health.
With endless health interventions out there, ranging from the 80/20 rule to exercise-free diets, it can be hard to gauge if you should prioritize diet or exercise — or if the answer lies somewhere in between.
This article tells you the benefits of exercise and diet, and if one is more important for your health than the other.
To lose weight you must be in a calorie deficit, meaning your body expends more calories than you consume. This can be achieved by eating and drinking fewer calories, burning more calories from physical activity, or a combination of the two.
Benefits of diet
While both diet and exercise are important for weight loss, it’s generally easier to manage your calorie intake by modifying your diet than it is to burn significantly more calories through exercise.
This may be why the 80/20 rule has become popular, as it states that weight loss is the result of 80% diet and 20% exercise.
For example, if you’re aiming for a daily calorie deficit of 500 calories, you could consume 400 fewer calories (80%) by eating lower calorie dishes, smaller portion sizes, and fewer snacks. Then, you only need to burn 100 calories (20%) from exercise.
For many people, this is easier than trying to burn 500 calories each day from exercise. Burning this many calories every day requires a significant amount of movement — plus, it’s time-consuming, taxing on the body, and rarely sustainable.
To illustrate, a person who weighs 154 pounds (70 kg) would need to cycle on an exercise bike for 1 hour at moderate intensity to burn 525 calories. Meanwhile, they could cut out 520 calories by skipping out on a venti Green Tea Frappuccino from Starbucks.
An easy way to manage calorie intake and promote weight loss without counting calories is to focus on eating whole, minimally processed foods that are high in fiber, protein, and healthy fats.
Benefits of exercise
There are many ways that exercise supports weight loss.
Strength training helps preserve and build muscle mass, which can increase your metabolic rate over time so your body burns more calories, even at rest. Furthermore, a single strength training session can increase your metabolic rate for up to 72 hours.
Aerobic exercise such as walking, jogging, or cycling — especially at a low to moderate intensity for 30 minutes or longer — can burn a significant number of calories in a single session and help promote a calorie deficit.
Regular exercise may also help manage hunger by regulating your hunger hormones. This may help prevent overeating and excess snacking. That being said, excessive exercise may increase appetite as well as injury risk, so moderation is best.
Finally, by burning extra calories and increasing your metabolic rate, regular physical activity allows you to have more flexibility with your diet, making weight loss more enjoyable and less restrictive.
Recommendation: Combination of diet and exercise
Although the 80/20 rule is a helpful guideline, you don’t have to follow it precisely. Instead, focus on making positive changes to your diet and exercise routine that work for you.
For instance, you may prefer achieving your daily calorie deficit 50% from diet and 50% from exercise. This means you’ll spend more time and energy exercising — but in return, you won’t need to limit your food intake as much.
The key for healthy, long-term weight loss and management is to use both diet and exercise.
In fact, one review showed that combining modest calorie restriction and exercise was the best way to achieve significant weight loss. In some cases, combining the two led to over five times more lost weight compared with using exercise alone.
Similarly, another review found that weight loss programs including both diet and exercise components had significantly greater weight loss results than interventions based on changes to either diet or exercise alone.
Ultimately, combining dietary changes and regular exercise can help you achieve more meaningful and sustainable weight loss in the long term.