6 Truths About Food and Exercise

Girl looking at mini pancakes seemingly sad.

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Riding the wave toward your nutrition and fitness goals is exciting, yet at times, can be a bit scary. One minute you feel like you're crushing it, the next you're wondering if you should change direction or try something else.

Diet and exercise information can come from all directions and it's not easy to decipher what's worth spending your time on and can, at times, be downright overwhelming. Should you avoid carbs or eat them? Eat less on rest days? Exercise before you can indulge?

With so many rules it can be hard to know what to believe. Fortunately, scientists are conducting research on diet and exercise myths. Many times, fads are often disproved and replaced with the insight you need. Here is are six truths about diet and exercise that you not only need to know but help dispel some common myths.

Balance Calories With Adequate Nutrition

Calories-in versus calories-out. It's the age-old theory for weight management. While it is true overall calories are the main predictor of weight loss, it doesn't have to be accomplished via exercise alone. Plus, this theory doesn't take into account the ways in which the body adapts to changes in eating patterns and exercise.

Creating a calorie deficit through a combination of exercise and diet is the most optimal way to lose weight. However, going on a diet alone isn't going to cut it.

Diet culture and restrictive meal plans tend to create a bigger problem for dieters than their original weight loss goal. Restricting calories too much and/or overexercising leads to disordered eating behaviors including binge eating, and eliciting hormonal changes that stimulate appetite and may be the reasons you're not losing weight.

Instead, focus on a balance of nutrients and adequate calories throughout the day that helps you feel full and satisfied. Giving your body the nourishment it needs while maintaining a small calorie deficit and/or incorporating regular physical activity will help you reach your goals without leaving you famished or feeling like you're missing out on all of your favorite foods.

Nourish Your Body on Rest Days

Because weight loss is the result of a calorie deficit over time, reducing your intake on rest days isn't necessary. Instead, rest-day nutrition is important for the recovery process. Skimping out on valuable calories from protein, carbs, and healthy fats may prevent you from recovering optimally and put you at greater risk of injury or even halt weight management progress.

And as it turns out, eating at more frequent intervals on rest days is associated with improvements in appetite and satiety. Rest days also are a great opportunity to nourish your body and take a break from your routine.

Tune in to your body's natural hunger and fullness cues. You may find you don't eat as much on rest days, or you may find the opposite. Listen to your body and eat accordingly.

Protein Shakes Are Optional

The window of opportunity to provide protein to muscles surrounding a workout isn't as small as it was once purported to be. While it is important to fuel up with protein daily to maximize your workouts and muscle-building potential, the type of protein and time in which you do so isn't as vital—unless muscle building is your goal.

You can still reap the rewards of increased protein consumption without rushing to gulp down a protein shake soon as you leave the gym. No matter what time you eat protein, the body will use it and direct it to the places it's needed most, like in the muscle after a tough sweat session. That said, if muscle building is one of your goals, a post-workout meal or shake with protein and carbs should be consumed within 1 to 2 hours after your workout.

But if you really just enjoy having a protein-rich meal or snack before and/or after you work out, that's fine too! Just know that it doesn't have to be a protein shake, It can be a protein-rich meal of whole foods like Greek yogurt, chicken, beef, eggs, soy, or whatever your preference may be.

Fuel Your Body Before a Workout

Fasted cardio sounds like a great idea—burn more fat while doing the same amount of work. But the reality is working out on an empty stomach doesn't result in any additional calories burned than if you had eaten beforehand.

Plus, physical exercise requires energy to perform optimally and without risk of injury. Skimping out on a meal before you workout starves your body of the nourishment it needs to accomplish a great workout.

What you eat before a workout doesn't have to be huge, even a banana will suffice. Putting food in your stomach is essential for getting a quality workout and you'll burn the same amount of calories anyway.

That said, if you are someone who feels sick, has acid reflux, or suffers from indigestion if you eat before a workout, do not feel like you have to eat anything. You have to do what is right for your body.

Prioritize Protein and Carbs Post-Workout

Ideally, you'll want to prioritize protein and carbs post-workout as these are the most important macronutrients for the recovery and refueling process. Whether or not they're low-calorie food options doesn't really benefit building muscle or weight loss after a workout. Not to mention, adequate refueling relies on appropriate portion sizes.

Undereating at any time, especially when participating in a fitness routine, can put you at greater risk of injury and can prevent you from reaching your goals. The International Society of Sports Nutrition's position stand on nutrient timing suggests a post-workout meal with 20 to 40 grams of high-quality protein within 2 hours of exercise as ideal for maximizing muscle-building potential. Achieving this in a low-calorie manner isn't really feasible.

You Don't Have to Avoid Carbs

The good news is you don't ever have to avoid carbs, including after a workout. Carbohydrates provide energy and play a role in many cellular processes. During exercise energy stores (glycogen) are depleted, so after a workout, carbs are important to replenish glycogen stores and help promote recovery.

The International Society of Sports Nutrition's position stand on nutrient timing reports consuming carbohydrates post-workout is an effective strategy to support increases in strength and changes in body composition. That means eating carbs after a workout can help you build muscle and burn fat.

The Concept of Earning Your Food Is Inefficient

The concept of earning food through exercise is inefficient and risky. Using ideas like "I've earned it," insinuates that exercise is a punishment. You're human. You don't have to earn your food and you deserve to enjoy food and exercise, not be punished for it.

When you put a negative connotation on diet and exercise, your attitude toward those things becomes negative and your relationship with food will decline. An unhealthy relationship with food can lead to disordered eating behaviors and an endless cycle of constantly wanting to lose weight or change your body.

Not to mention you could be chasing a ghost. We often underestimate the number of calories burned through a workout and the number of calories in food can vary dramatically. In that sense, matching food with the number of calories you burned during your workout is almost impossible.

Instead, try changing the way you talk (and think) about diet and exercise. If your reason for eating or exercising is negative or if you are only focused on the physical result, those may not be the right reasons. If it's just simply because you enjoy it, it improves your mood, or you can sleep better, then you're on the right track.

A Word From Verywell

You know your body best—not whoever is offering you trendy diets or social media hype. Your fitness and nutrition journey is going to evolve and change. Focus on listening to your body and practicing sustainable habits.

The next time you hear diet or fitness advice, take a moment to do your own due diligence. Where did the information come from and what kind of research is out there supporting it? If you're having trouble understanding the data or find yourself struggling with your mindset around food and exercise, a healthcare practitioner or registered dietitian can help you discern fact from fiction and find what works best for you.

Frequently Asked Questions

  • Is it OK to skip dinner if you are not hungry?

    Skipping dinner here and there isn't a problem. Doing so regularly can lead to malnourishment, nutrient deficiencies, weight gain, interruptions in bowel movements, lack of energy, and can lead to an unhealthy relationship with food and/or disordered eating behaviors. If you're not hungry but you know it's time to eat, opt for a light snack instead.

  • What are the signs you are not eating enough?

    The signs of undereating include lack of energy, sleep disruptions, lack of focus, poor strength and stamina, constipation, anxiety, inability to get pregnant, irritability, mood swings, constantly feeling cold, irregular period, and unhealthy hair and nails.

  • Can too much exercise cause weight gain?

    Too much exercise, or overtraining, can cause weight gain however the mechanism of action isn't clearly defined. It's believed that hormonal changes from overtraining are responsible for most of the symptoms including changes in body composition. It is worth noting that this most often occurs with elite athletes or those trying to reach peak performance. Adequate rest between workouts and optimal nutrition can prevent overtraining and the symptoms that come along with it.

12 Sources
Verywell Fit uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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By Shoshana Pritzker RD, CDN, CSSD, CISSN
Shoshana Pritzker RD, CDN is a sports and pediatric dietitian, the owner of Nutrition by Shoshana, and is the author of "Carb Cycling for Weight Loss." Shoshana received her B.S in dietetics and nutrition from Florida International University. She's been writing and creating content in the health, nutrition, and fitness space for over 15 years and is regularly featured in Oxygen Magazine, JennyCraig.com, and more.