What’s More Important When Losing Weight: Diet or Exercise?

Losing weight—fat, specifically—is a common goal for many, especially as summer approaches. Being within a normal weight range not only allows you to look good, boosting confidence, but also staves off potential health concerns; obesity is linked to increased chances of diabetes, heart disease, and cancer, among other issues. Getting healthy is always an admirable goal.

To achieve our desired fat loss, we must be in an energy deficit; in other words, our body must spend more energy than it consumes. This can be achieved by consuming less energy, AKA dieting, or by burning more energy, AKA exercising.

It’s not clear, however, which is the better approach to weight loss: diet, exercise, or a combination of both?

What Dieting Does to Your Body

Consuming fewer calories than you take in creates an energy deficit. Eating at a level below your basal metabolic rate allows the body to use fat stores for energy, which is how you shed excess weight.

One pound of fat is roughly equivalent to 3,500 calories. Eating 500 calories fewer than your body spends daily would result in about one pound lost per week.

What Exercise Does to Your Body

Exercise costs energy. Whether you’re working a little or a lot, all movement requires the body to spend energy.

Training by kettlebell

Similar to the above example, if you ate equal to your BMR each day, but also burned 500 calories exercising each day, you would still lose that same pound each week.

So Which Approach is Better?

In the end, the body only reacts to the energy deficit you place it in. As far as fat loss is concerned, creating that deficit via diet or exercise is not going to make much difference.

Researchers in the US conducted a study that looked at people losing weight via diet, exercise, or both—all at an equal 20% caloric deficit. The results may interest some: all three groups lost similar amounts of weight over the same time. This proves that the deficit is the ultimate deciding factor in how much, and how fast, you shed fat.

Of Course, It’s Not That Simple…

The study, while interesting, was looking strictly at weight loss. Which is important—but it isn’t everything. A nutritious, balanced diet allows the body and brain to functional optimally. Without the right vitamins and minerals, we won’t perform well, whether in the gym or at work. Without enough protein, we may lose muscle mass in addition to fat.

Would you fill your Ferrari with the cheapest gas available? Maybe you would, but the car would almost certainly let you know it was not pleased with your decision. Treat your body with respect and it will respond accordingly.

And exercise is just as important. Cardiovascular work improves the health of your heart and lungs, and improves blood and oxygen flow throughout your body, creating an efficient system. Meanwhile, resistance training builds lean mass—which passively burns extra calories—while improving bone density and, frankly, making you look better.

It’s worth noting that in the study, all groups lost the same weight, but the resistance training group retained all of its lean mass, while the other two groups lost some (1.6% for the hybrid approach and 2.5% for the diet-only group). However, they exercised for around 7.5 hours per week, while the hybrid group only exercised for 4.5 hours per week. Your lifestyle may suit one approach better than the other.

The Final Word

Decide approximately how much weight you want to lose. Decide on a rough timeframe to reach this goal. (I recommend no more than one pound per week, as anything more is often challenging for most individuals and may result in excessive cheat days, or yo-yo dieting, which gets you nowhere.) Calculate your BMR and determine the daily deficit required to hit your weekly fat loss goal.

From there, the rest is up to you. A balanced combination of cardio work, resistance training, and dieting may not necessarily yield results faster than a singular approach, but it certainly makes it easier—this way, you don’t have to work out every day, nor do you have to eat minimally every day. I suggest a balanced approach of working out three to six times per week, balancing cardio and resistance sessions, while eating clean and healthy whenever possible.

There are no magical solutions to fat loss. It takes time and effort. But the reward is a healthier, happier body—and a healthier, happier you.