Here's What a Dietitian Thinks About Skipping Breakfast Before a Workout to Lose Weight

The fast track to weight loss isn't always "eat less, lose more," especially when you factor workouts into the picture. If you work out early in the morning, in particular, you might be used to skipping breakfast or your pre-workout snack. It's early, dinner feels like it just happened, and you don't want to eat too much and upset your stomach. And when your goal is weight loss, it's hard to imagine that eating more, even right before a workout, can really help you reach your goals. If your stomach isn't growling, do you really need to eat before your workout?

Should You Eat Before a Morning Workout to Lose Weight?

As it turns out, working out on an empty stomach in the morning can actually make it harder to lose weight. "It may mean that you don't work out as hard or as long because your body doesn't have the necessary energy," said registered dietitian Audra Wilson, LD, bariatric dietitian at the Northwestern Medicine Metabolic Health and Surgical Weight Loss Center at Delnor Hospital. And the more intense your workout (think HIIT), the more energy you expend and the more important your pre-workout fuel becomes, Audra told POPSUGAR.

The reasoning? Your body uses less energy when you sleep, Audra said, but you're still burning some calories, which means you might not be able to coast through your morning workout on last night's dinner alone. Having less energy can negatively impact your workout, which in turn can make it harder to lose weight. As Audra put it, "If you skip a pre-workout snack, you may burn less calories overall and be miserable doing it. Fueling for exercise can improve overall performance and allow you to exercise longer and harder."

Many people swear by fasted cardio as a form of weight loss, especially for burning fat. Research is conflicting, but no study has convincingly proven that fasted exercise gives you significant weight loss advantage, Audra told POPSUGAR. Either there was no difference between breakfast and no breakfast in terms of weight loss, or fasted exercise was shown to provide some advantage, but exercise in general (fasted or not) was found to be the biggest factor in losing weight.

To some extent, it comes down to what works best for you. "Some may be able to exercise fasted," Audra said, "but the benefits of a pre-workout snack are many." Besides helping you perform better, eating before a workout can help you avoid injury and improve your body composition over time, Audra explained. With that in mind, if you wake up hungry, definitely grab a bite; if you don't, head to the gym and see how you feel. Even if you think you work better without a snack, try having a small one beforehand to see how it affects your workout. You might not realize how much more energy you have to put in, given some extra fuel.

What Should You Eat Before a Morning Workout to Lose Weight?

For a pre-workout weight-loss-optimized snack, go for a 3:1 carb-to-protein ratio for cardio exercise and a 2:1 ratio for strength training, Audra said. "The key is to keep fiber and fat content low," she explained. Fiber speeds up your digestion and fat slows it down. Too much of either before a workout can upset your stomach or have you running to the bathroom.

For cardio, your body's main source of energy is glycogen, which is a stored form of glucose that you get by eating carbs. "Glycogen is stored in the muscles to use when those muscles are activated in activities like walking, running, using the elliptical, or bike," Audra explained. Going into cardio with depleted glycogen stores might make you feel lethargic and unable to complete your workout. For a morning snack before cardio that'll keep your energy up and help you lose weight, eat:

  • One cup of grapes or berries with a low-fat cheese stick or Greek yogurt
  • Low-sugar cereal with milk
  • Toast with a hard-boiled egg

For a snack before morning strength training to help you lose weight, eat:

  • A small apple or half a banana with almond butter
  • Half an English muffin with low-fat cheese

Make sure to give yourself some time to digest your snack, anywhere from 15 minutes to an hour depending on what you choose. Here's more on what and when to eat before a workout.

Whatever you choose, Audra's recommendation was to always fuel up before a workout, even if you're not hungry. "A small snack will replenish glycogen lost overnight and provide energy for the workout ahead," she said. Without some fuel, and especially without some kind of carb, you risk feeling fatigued, getting injured, and even losing muscle mass. With those kinds of potential consequences, it's definitely worth a shot.