Is exercise necessary for weight loss? Or can you just cut cals to drop lbs? Is there really any need to get super sweaty and worked up?

So, can you lose weight with diet only?

Yes. As long as you take in fewer calories than you burn, you’re likely to lose weight.

Whether you’re trying to reduce, increase, or maintain your body weight, it’s important to create a sustainable, safe, and enjoyable eating pattern.

So, on top of changing their diet, people who are trying to lose weight will typically bump up their activity levels to create a larger calorie deficit. This allows them to follow a less restrictive diet and eat more of what they enjoy.

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We lift the lid on how diet, exercise, and weight loss work in tandem.

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Design by Viviana Quevedo; Photography by Martí Sanz/Stocksy United

Yep. You can lose weight without exercising or increasing the amount of physical activity you do — as long as you burn more calories than you take in.

Plenty of factors contribute to weight gain. But the main causes typically involve consuming too many calories and not getting enough physical activity.

Creating a calorie deficit encourages weight loss. You can create a calorie deficit by reducing your calorie intake, increasing your activity level to burn more calories, or both.

However, physical activity and exercise — which are two different things, BTW — do so much more for your health than help you maintain body weight changes. A balanced, healthy lifestyle is the one.

Let’s compare the research on losing weight through calorie restriction only with the studies on a calorie restriction and exercise combo and see who wins. Rapper to our left, introduce yourself…

Diet alone

It is possible to lose weight through dietary changes alone. To do this, you need to create a calorie deficit, meaning taking in fewer calories than you burn each day.

For example:

  • You usually consume 2,500 calories per day and stay in a calorie surplus (you take in more calories than you burn).
  • You reduce your calorie intake by a few hundred calories per day, creating a calorie deficit.
  • Voila! Weight loss (probably).

The more calories you cut from your intake, the faster you’re likely to lose weight. But cutting calories too drastically is not healthy and won’t help you in your quest to maintain and manage your weight long-term.

Low and very low calorie diets can cause compensatory changes in your body, including:

This makes it harder to maintain weight loss over time.

That’s why experts recommend making smaller cuts in calorie intake that minimize these side effects while encouraging a more sustainable form of weight loss.

Diet plus exercise

Sure, you can lose weight without changing your activity levels. But research shows that combining calorie reduction with increased physical activity is more effective than just cutting calories. So put that in your NutriBullet and blitz it.

For example, a 2021 study randomized 239 people with higher body weights into four groups:

  • a calorie-restriction-only group that acted as the control group
  • a group that restricted calorie intake but also did strength training
  • a group that restricted calorie intake but took part in endurance training
  • a group that combined calorie restriction, strength training, and endurance training (phew!)

All participants followed a diet that created a 25 to 30 percent calorie deficit. They followed this eating plan for 6 months. Peeps in the exercise groups did supervised exercise routines 3 times per week.

(Of the 239 who started the study, 180 reached the finish line — weight loss is, somewhat ironically, no picnic.)

As expected, all the groups lost similar amounts of weight on the calorie-restricted diet.

But after 3 years, most of the groups had gained back most of the weight they’d lost. The only exceptions were in the group who followed the diet and smashed out strength and endurance workouts. They kept off a good amount of the body fat in the long term.

And that’s what you want, right? Sustainable change and lifestyle choices that last?

Plus, even though weight loss was similar among the groups, the exercise groups lost more body fat and maintained their lean mass. The control group lost lean mass.

Maintaining lean mass during weight loss is important. Losing muscle can screw with your metabolism, making it harder to maintain your weight. Which… kinda defeats the point.

Is cardio/endurance better than resistance training for weight loss?

A 2015 review of 66 studies found that programs combining reduced-calorie diets with exercise were better at reducing body fat and retaining lean mass than those focusing on diet alone.

The researchers found that resistance training was especially effective for boosting fat loss and supporting maintenance of lean mass.

In reality, the best exercise for weight loss is whatever gets you off your butt and moving around in combo with a calorie deficit.

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A 2012 study of 399 women after menopause found that those who followed a calorie-restricted diet and took part in an aerobic exercise program lost:

  • 8.4 percent more weight than women following exercise-only programs
  • 2.3 percent more weight than women following a low calorie diet

So, although it’s possible to lose weight through cutting cals alone, it’s more effective if you add in a bit of physical activity for good measure.

The verdict: Weight loss through diet alone vs. diet and increased activity

Weight loss through diet alone is possible.

But studies show that upping activity levels in combination with calorie reduction is most effective for fat loss and maintaining muscle mass.

Go get ’em, tiger!

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Interested in losing weight and improving your health? Focus on including more nutritious foods in your diet to promote weight loss. It doesn’t have to taste or feel like punishment.

Are certain dietary patterns better than others?

The most important factor in weight loss is creating a calorie deficit. Period.

That means you could technically lose weight on a doughnut-only diet, as long as you stay in a calorie deficit. (Doughnut do that, BTW. We’ll keep making bad puns until you stop.)

What’s the healthiest diet for long-term weight maintenance?

Some research suggests that certain diets are more effective than others for long-term weight maintenance and improving other markers of health.

The “best” dietary pattern is any healthy eating plan you can stick to long-term. Yes, even when you’re on vacation, out to lunch, or enjoying a holiday meal with the fam. You guessed it — flexibility is key.

Also, any healthy diet should include lots of whole, nutrient-dense foods, especially fruits and veggies.

Shocker: Diets high in produce and whole foods have strong links to healthy body weight and long-term weight maintenance.

For example, the Mediterranean diet — one that’s full of produce, nuts, seeds, olive oil, fish, and beans — is one of the most effective and sustainable dietary patterns for reducing weight gain, promoting healthy body weight, and reducing chronic disease risk. Bellissimo!

Some other dietary patterns. such as vegetarian and low carb diets, can also be effective for weight loss.

Disclaimer: Low and very low carb diets tend to lead to rapid weight loss in the short term. But in the long term, their weight loss results are similar to those of other dietary patterns, such as low fat diets.

Some diets may also be more appropriate for certain people. For example, a low carb diet may help bring down high blood sugar and triglyceride levels in people with metabolic syndrome.

Searching for the best diet for weight loss is like trying to define the best type of hat. Everyone is different, with varying needs, tastes, goals, and health concerns. And trilbies are a terrible idea in both scenarios.

Consider what’s best for you personally when putting together your weight loss eating plan.

Calorie needs are highly individualized

Everyone has different calorie needs. They depend on a whole bunch of factors, including:

  • body size
  • activity levels
  • age
  • overall health

If we were all identical, it would be handy for nutritionists but very, very boring for everyone else.

So, randomly following a low calorie diet that you found online may backfire. It might be completely inappropriate for your specific needs.

If you include exercise in your program or simply increase your activity levels, you’ll likely be able to create a calorie deficit by increasing how much energy you use. This means you don’t have to cut as many calories. (Yay!)

TBH, working with a qualified healthcare professional who specializes in nutrition (like a registered dietitian) is the best way to create a diet plan that’s right for you.

They can help you determine your calorie needs and build a healthy, sustainable weight loss plan.

So you don’t technically *need* to exercise for weight loss. But being active is important for SO many other aspects of health. Plus, it’s fun! Physical activity can include gardening or taking your doggo for a walk. What’s not to love?

Adding exercise to your routine can help:

Exercise and physical activity are both super and duper important. Weight loss is just one of the many benefits that come with bumping up the amount of physical activity you do.

But balance is always key. Just as too little exercise can negatively affect your health, too much exercise can also be harmful.

If you’re not very active but want to start adding some joyful movement to your day, start by going for a walk. Walking is mega underrated and safe for exercise newbies.

When you’re choosing a new activity or workout, make it something you actually enjoy and can see yourself doing for the foreseeable future. Even if that means just going for a daily walk in the afternoons and stretching at night.

Moving that bod is what’s most important.

Sure, you can lose weight through diet alone. But combining a healthy dietary pattern with exercise is usually more effective for burning fat and maintaining muscle mass.

The most important factors when creating a diet or workout plan are safety, flexibility, and sustainability. Your diet should fuel your body with enough calories and nutrients to support peak health.

And your exercise routine should be hella fun and make you feel good about yourself.