Should You Eat before or after Your Workout to Lose Weight?

Craig Primack, MD, FACP, FAAP, FOMA

Reviewed by Craig Primack, MD, FACP, FAAP, FOMA

Written by Vanessa Gibbs

Updated 04/30/2024

You’re heading out the door for a workout when you spot some cereal and realize you’re hungry. What do you do? If you’re trying to lose weight, should you eat before or after your workout? 

Honestly, the science doesn’t come down hard either way. So we say, just do what feels right for you. You’re working out! That’s the most important thing here.  

Focus on eating nutritious foods and getting movement in — no matter the order.  

When it comes to weight loss, studies show that it doesn't make too much of a difference whether you eat before or after you exercise. 

Below, we dive into the science behind eating before or after a weight loss workout, including whether to eat breakfast before or after a morning workout, whether to schedule a workout before or after dinner and which foods can maximize your workout’s impact. 

Eating before a workout has some benefits. 

You might feel weak or just really low on energy if you don’t eat something before you work out — especially if it’s going to be an intense session like weightlifting or a boot camp class.

Beyond feeling better, you might also perform better if you eat something before you get started.

A review of research studies found that eating ahead of time enhanced performance during prolonged aerobic exercise. 

So, if you’re headed out on a long run or bike ride, you might want to eat first. But the same may not be true for your 30-minute spin class. 

For starters, you might find you feel sluggish or have some digestive discomfort like cramping if you eat before a workout. 

Insulin and glucose concentrations (blood sugar levels) were also significantly higher when participants ate before exercise. 

Exercising in a fasted state — so this might mean working out before breakfast or before dinner when lunch was hours ago — may have its own benefits. It may help promote weight loss. 

Your body might break down more fat for energy when you don't eat before working out. 

One small study found that people working out on an empty stomach burned more fat than people working out after a meal.

Sounds promising right? 

But before you rearrange your meal and exercise times, the review concluded that these results only looked at the short-term effects of fasted exercise. Whether these fat-burning fasted cardio workouts actually contribute to weight loss over time, we just don’t know. 

But eating after your workout has other benefits. For example, eating protein after a workout may aid muscle recovery and growth. 

The bottom line: Eat a meal soon after exercise if you’ve worked out in a fasted state.  

Research has shown that whether you eat before or after a workout working out doesn’t play that big of a role in weight loss. 

For example, one study included 20 women split into two groups: a fasted training group who exercised in the morning before breakfast, and a fed training group, who ate a meal before exercising. 

(The women either had a meal replacement shake before working out or after.) 

The women did one hour of aerobic exercise three days a week for four weeks and they all followed eating plans designed to put them in a caloric deficit — meaning, they ate fewer calories than they burned. 

Ready for the results? Both groups lost weight and fat mass, but there wasn’t a significant difference between the two groups. 

The study was small, but other research backs it up.

A review of studies looked at whether overnight fasting before aerobic exercise affected weight loss. 

The results showed that — wait for it — there wasn’t much of a difference. Whomp whomp. 

Eating before working out vs. eating after working out had: 

  • A small effect on body fat percentage 

  • A trivial effect on muscle mass in women 

  • A trivial effect on body mass  

Keep in mind: There were only five studies in this review, including 96 participants in total, which isn’t enough research to rest the case on. 

Finally, many studies look at eating before or after aerobic exercise, but what about high-intensity interval training (HIIT), like sprints or CrossFit?

One study followed 16 women doing 18 HIIT sessions over six weeks in either a fasted or fed state. The women did 10 sets of 60 seconds of intense cycling followed by 60 seconds of recovery. 

Body fat percentage decreased and fat-free mass — like muscle — increased in both groups. 

But, yet again, the results found no significant difference between working out fasted vs. working out fed. 

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Final verdict time, should you eat before working out or wait until after? 

Drumroll please…it may not matter that much. 

Eating before a lengthy exercise may help performance. But some research suggests that you may burn more fat during fasted exercise — though this doesn’t seem to affect the amount of weight people lose.  

Several studies show that working out fasted vs. fed doesn’t make that much of a difference to weight loss. 

Plus, many of the studies looking at meal and exercise timing are small, so we’ve got to take the results with a pinch of salt. 

There’s no single best way to lose weight and the most important factor is being in an energy deficit.

As for physical activity, there are no guidelines on when to eat, just how much to do. 

You should try to aim for at least 150 to 300 minutes of aerobic exercise — like brisk walking, swimming or cycling — each week and consider strength training at least twice a week. Beyond exercise, doing more general movement each day can help with weight loss and staying healthy. 

In the end, it might just come down to personal preference. Essentially, when it comes to eating before or after exercise, you do you!

Should I eat before or after a workout to lose belly fat? And what about dinner and snack timing? 

You aren’t alone if you find yourself wondering these things, but there aren’t any hard-and-fast rules when it comes to meal and exercise timing for weight loss. 

And as the studies above show, the order of operations might not make that much of a difference when it comes to weight loss. It might affect how you feel and recover though. 

When to Eat before a Workout

Eating a large meal and then immediately hitting the gym isn’t going to be a fun time.

It’ll be different for everyone, but you might find you feel better eating a small snack, instead of a meal, shortly before working out. 

Alternatively, consider eating a pre-workout meal but waiting a couple of hours before you exercise, so you’re not working out with a full stomach. 

If you like working out first thing, you might question if you should eat breakfast before or after a workout. Again, that’s personal preference. You could work out on an empty stomach and then eat breakfast shortly after, or you could eat a small snack before you exercise.

When to Eat after a Workout

There are no set rules for when to eat after a workout, either. (Helpful, we know.)

If you’ve worked out fasted — perhaps first thing in the morning before eating breakfast — you don’t want to get in the habit of not eating after your workout to lose weight. 

It’s important to eat a meal with protein and carbs after exercise to promote muscle protein synthesis and reduce the breakdown of protein — aka help your muscles recover and grow. 

If you’ve eaten one to two hours before exercise, your body will still have the nutrients from this meal in your system, so you wouldn’t need to eat another meal immediately after working out.

But if you’ve worked out before lunch or dinner, your last meal may have been many hours before. 

The advice here is, if your last meal was about three to four hours before working out, eat a meal with at least 25 grams of protein soon after exercising to aid muscle recovery and growth. 

To be honest, much of the research on pre- and post-workout nutrition focuses on building muscle, not weight loss. Ultimately, you should make the choice that feels right for your body and your fitness goals.

Eating the right foods may be more important than whether you eat before or after exercise. 

Whenever you decide to eat, go for nutritious whole foods and a balance of macronutrients — protein, carbs and fats — to fuel your body and promote recovery and weight loss. 

What to Eat before a Workout to Lose Weight 

You might want to go for a light snack if you’re eating immediately before a workout. 

Pre-workout snack ideas include: 

  • A piece of fruit and some peanut butter 

  • Low-fat Greek yogurt topped with nuts and berries 

  • Hummus and veggies  

Check out our guide to healthy snacks for more inspo.

What to Eat after a Workout to Lose Weight

Go for a well-rounded meal if you worked out fasted or your last meal was a few hours ago.

Post-workout meal ideas include: 

  • Oatmeal topped with seeds and dried fruit  

  • Chicken and veggies in a whole-grain wrap 

  • Lentil curry with mushrooms, spinach and sweet potato 

  • Brown rice, grilled fish and veggies  

If you can’t or don’t feel up to eating a full meal straight away, consider a snack with protein and carbs, like low-fat chocolate milk or a protein bar and banana. 

And don’t forget hydration. Drinking enough water throughout the day can not only keep you hydrated for your workouts. It can also help regulate your appetite and promote weight loss. 

If you’re still not sure what to eat before or after your workout, try reaching out to a healthcare provider or a registered dietitian for personalized advice.

When it comes to weight loss, eating nutritious foods is important, but nutrient timing around exercise isn’t as clear-cut. 

Here’s a recap of the key advice: 

  • Eating before a workout. This can help with performance if you’re exercising for long periods of time, or if you feel weak or have low energy levels when you exercise on an empty stomach. Consider eating a small snack as pre-workout nutrition or working out a couple of hours after a meal.  

  • Eating after a workout. Eating fasted may boost fat oxidation and eating after your workout is important if you worked out fasted or haven’t eaten for a few hours. If it feels good for you, you can work out before breakfast or well after lunch before having dinner, for example.  

  • What you eat may be more important. You want to make sure you’re properly fueling your body with the best foods for exercise and giving it the lean protein it needs to recover, but current research suggests that it might not make a difference whether you eat before or after exercise. 

Beyond meals and exercise, remember to drink enough water and get enough sleep to promote weight loss, improve your overall health and feel your best. 

For some, weight loss medication can help you reach your goals. 

If you’re interested, our free assessment can help you determine which — if any — doctor-trusted weight loss treatment plan could be a good fit for you.

9 Sources

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