When you want to lose weight, there are two options Either you can start dieting or start exercising. Ideally, you should do both. But which of the two helps you lose weight faster?

The answer, according to multiple studies and experts, is diets help in faster weight loss. But it's not that simple, even though we all want a magic solution to dramatically reduce our weight without much effort or sacrifice.

Important Note Before We Start

This article addresses concerns for people without any specific weight-related diseases. If you have a weight-related disorder, or suspect you might have one, please seek a professional's medical opinion.

What Science Says

Study after study has confirmed that for weight gain or loss, what you eat is more important than your physical activity. A meta-analysis of studies showed that there is no association between physical activity and fat mass in children.

Exercise has many health benefits like better moods and lowered risk of diseases, but it does not help you lose weight, according to research by Loyola University Chicago Stritch School of Medicine.

The basic science of weight loss is pretty simple. It's all about calories:

If you consume fewer calories than you expend, you will lose weight.

The Calorie Equation

How many calories will help you lose weight? The oldest and most widely accepted equation is that 3,500 calories equals one pound of fat.

You can lose those 3,500 calories in two ways. You can either burn those calories through exercise or you can reduce 3,500 calories in what you eat.

To burn 3,500 calories, you need to run for 4--6 hours or walk for 9--11 hours. Spread over a week, that's roughly an hour of running on the treadmill per day.

diet exercise supertracker

And that's the low estimate. The USDA and the National Institutes of Health estimate one pound of fat loss might need 7,000 calories, according to new research. They have made a wonderful tool called SuperTracker to plan your weight loss based on their parameters. It's not perfect, because of how fitness apps calculate calories, but it's a start.

Why Exercise Doesn't Work in the Long Term

As important as exercise is, its effects on pure weight loss aren't major. For example, the world's strongest men exercise for hours every day, but they're not exactly lean, are they?

diet exercise treadmill

Nutritional biochemist Shawn H. Talbott says that weight loss is 75 percent diet and 25 percent exercise. He believes it's much easier to cut calories than burn them off. And he offers a great mantra:

"You can't out-exercise a bad diet."

The science holds up this idea. Researchers found that our bodies adapt to higher activity levels. Even if you exercise more, you don't necessarily burn more fat -- a fitness band will help lose weight, but it's not a long-term solution without dieting.

Which Diet Is Best?

Now that you know diet is the way to go, you need to decide which diet works the best. Should you go for keto or the South Beach diet? Maybe you need to start on Atkins. Here's the secret: none of them are better than another, they're all just as effective.

In 2014, a meta-analysis of different studies found that any low-carbohydrate or low-fat diet led to significant weight loss. But no named diet was significantly better than any other. And the conclusion was simple:

"The best diet is the one that you will adhere to."

But don't mock named diets. While one isn't superior to another, the studies show that they are all good for weight loss. Where they help the most is in defining parameters for you. Once you know what you can eat and what you can't eat, you can create a personalized meal plan accordingly.

If you want a nudge in the right direction for a named diet, try the BBC's test to find the right diet for you.

It might be best to learn nutrition principles and then make your own diet. There is a widely accepted thumb rule you can follow: a healthy daily calorie count is 10 calories per pound of body weight. That means a 200-pound person should have 2,000 calories per day.

How to Measure What You Eat

Whichever diet you go for, you need to track what you eat. To do that, download calorie counter apps on your smartphone.

My recommendation would be MyFitnessPal, available for free on Android and iOS. It's essentially a food journal that makes your job easier. The app's database has an incredible catalog of foods across different cuisines. Find what you ate, add it in, and the app does the rest of the work.

Over time, you'll get a clear indication of how many calories you are consuming. If you are augmenting your diet with exercise, MyFitnessPal has calorie-burn estimates for common workouts. Add those in too, to see how you are balancing your calorie ratio.

Download -- MyFitnessPal for Android or for iOS (Free)

Do Both!

While the science is clear that diet offers faster weight loss, it would be foolish to only diet and not exercise. The benefits of diets cannot compare to the health benefits of exercise. And remember:

"Losing weight" is not the same as "being healthy."

Several long-term studies have shown that the best way to lose weight and keep it off is by doing both diet and exercise. "Energy Balance" is the key, says the American College of Sports Medicine, and urges us to look beyond the diet vs. exercise debate to focus on "diet and exercise" instead.

Start both together: The Stanford University's Medical Center found that you have higher chances of sticking with your new healthy routine if you change diet and exercise habits at the same time. Changing one first and then the other reduced the number of people who followed up on their new habits.

If you're ready for it, we have some fantastic Excel templates to track health and fitness.

Diet vs. Exercise: Your Experiences

I found that going on a diet was the big contributor to my weight loss, and regular exercise helped me keep the weight off in the long term.

Weight losers, what has been your experience with diets and exercise? Which of the two worked better for you to lose weight faster, and which stuck in the long-term?

Image Credit: Kinga Kijewska via Shutterstock.com