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How Exercise Affects Appetite and Hunger, and What This Means for You

Have you ever finished a workout and felt like you need to eat a huge meal? Have you finished a workout and felt like you weren’t hungry, even though you thought you would be? Both of those situations are realistic examples of how exercise impacts your appetite. You may think exercise will always make you hungry, but it’s actually more nuanced than that.

Exercise has the ability to either increase or decrease your appetite, depending on the type of training you are doing, your physiology, and your current diet. Knowing how exercise affects hunger can help you plan your pre and post-workout nutrition as well as strategize your meal intake to boost the fitness progress you’re working toward.

Hunger vs. Appetite 

Hunger and appetite are not one and the same. Hunger is a physical sensation caused by hormones and chemical reactions that occur when your body senses that it requires more food. This reaction can happen for a variety of reasons.

Appetite is a psychological reaction that can be a learned response or occur due to triggers like boredom, emotions, seeing, or smelling tempting foods. These triggers can cause you to eat even when you’re not hungry. Several hormones regulate hunger, appetite, and digestion.

The terms hunger and appetite are often used interchangeably, even in scientific literature, but using the words to describe separate functions is helpful for explaining the differences between psychological and physiological desires for food.

An important point to keep in mind always is that nutrient-dense foods that fuel your training and help your body repair after exercise are vital. Regardless of your goals, focusing on food quality is essential for optimal performance and wellbeing.

Hormones That Control Hunger 

There are several hormones and hormonal interactions that influence hunger. Understanding how these hormones affect hunger will provide context for how different forms of exercise interact with these hormones and, therefore, hunger. Here are the significant influencers:

  • Leptin: Increased leptin levels trigger the hypothalamus to decrease hunger. Leptin is secreted by adipose tissue (body fat) into the bloodstream.Higher levels of leptin coincide with higher body fat levels and increase with food intake.
  • Ghrelin: Ghrelin works with the hypothalamus to increase hunger. It is produced by the stomach and small intestine when your stomach is empty.
  • Adiponectin: Adiponectin is secreted by fat cells and goes up as your level of body fat goes down. Conversely, when your body fat levels increase, your adiponectin levels decrease.
  • Cholecystokinin: Cholecystokinin is produced in the small intestine during and after eating. It triggers bile and digestive enzymes to release into the small intestine, suppresses hunger, and increases feelings of fullness.
  • Peptide YY: Peptide YY suppresses hunger for about 12 hours post-meal. It is produced in the large and small intestines.
  • Insulin: Insulin regulates blood sugar levels and suppresses hunger. It is produced in the pancreas.
  • Glucocorticoids: Glucocorticoids in excessive amounts increase hunger while a cortisol deficiency can reduce hunger. They are made by your adrenal glands and have several functions including regulating inflammation.

The Effects of Intense Exercise 

Research on the effects intense exercise has on hunger points to a blunting effect, meaning that your HIIT session could cause reduced feelings of hunger afterward. This effect may not reduce overall calorie intake on the day of training, but instead, blunts hunger for a while after the workout, according to some research. However, the scientific consensus on this is mixed.

A study that monitored the levels of certain hunger hormones after intense forms of exercise, showed that ghrelin and appetite were suppressed after high-intensity continuous training. Blood samples were obtained immediately pre-and post-exercise, as well as 30- and 90-min post-exercise.

While these effects were also seen with moderate-intensity continuous training, they were highest after sprint interval training. In this particular study, energy intake was reduced on the day after high-intensity continuous training compared to both moderate intensity and the control group which did not exercise. This study monitored calorie intake the day before, day of, and day after the exercise and revealed a decrease in overall caloric intake on the day after.

Compensatory intake is a critical factor to consider. What this term means is whether or not the suppression of hunger lead to an overall decrease in calorie intake or not. If hunger is reduced but it doesn’t change how much you end up eating over time, then it makes little to no difference to your calorie balance (calories in versus calories out).

The Effects of Moderate Exercise 

Moderate exercise has been shown to affect hunger, appetite, and calorie intake in various ways. Several studies have shown that most individuals don’t experience compensatory changes in hunger after moderate-intensity exercise.

Moderate sustained exercise can suppress appetite with an increase in peptide YY, which suppresses appetite for about 12 hours. What this means is that moderate-intensity exercise, which burns calories, thereby increasing your calorie output, does not cause hunger that leads to increased food intake. That being said, eating after you exercise is crucial for restoring glycogen and repairing muscle.

Studies have concluded that moderate exercise can delay hunger but does not reduce food intake.12 However, it also does not increase food intake compared to sedentary individuals. This means you can create a calorie deficit using exercise that will not be lost through eating more later if that is your goal.

If your goal is to gain or maintain your weight, or increase performance, you may need to purposefully increase your calorie intake if you participate in exercise. Adding slightly more to your regular meals, especially in the form of nutrient-dense protein and carbohydrates, can support your training and help you gain lean mass.

Strength Training and Hunger Regulation 

Strength training can be performed at light, moderate, and intense levels, depending on the type of training you do. For instance, resistance training with more extended sets using multiple reps and lighter weight may not increase the heart rate too much, while powerlifting performed with heavier weights can increase the heart rate to near maximum.

Strength training, however, is unique from traditional cardiovascular training in that it causes more damage to the muscles than other types of exercise often do. This type of damage is necessary for muscles to become stronger and larger.

Some research suggests that strength training can lead to a significant increase in appetite. However, others have suggested no increase in caloric intake. If your aim is to build muscle and increase your lean mass, it is likely you will need to make a conscious effort to consume more calories, not only to build the new tissues but to compensate for the calories burned during your training.

Although less likely, you can build muscle and lose fat at the same time, especially if you are new to strength training. In this case, you will need to create a small calorie deficit while being sure to consume enough protein to support muscle tissue development.

How These Effects Can Be Used Toward Your Goals 

Adding exercise to your lifestyle provides many benefits to your health and wellbeing, far beyond bodyweight. However, you may also have specific goals related to your weight, including reducing body fat, gaining muscle, fueling performance, or maintaining your weight. In that case, there are some things to consider regarding how your training may affect your appetite.

Weight Gain and Building Muscle 

If your goal is to maintain or gain weight, you will likely need to increase your calorie intake when adding exercise to your lifestyle to make up for the calories lost. To build muscle and increase your lean mass, you will need a greater calorie intake with a special focus on getting enough protein.

You can try adding a bit more food to each meal or add an additional meal, such as post-workout refueling. Try to focus on nutrient-dense foods that will fuel performance for the best results, in particular, complex carbohydrates, and lean protein.

Examples of healthy foods to add include eggs, fish, tofu,chicken, lean cuts of beef, beans and legumes, whole-grain breads, starchy vegetables, sweet potatoes, oats, and quinoa.

Weight Loss and Losing Bodyfat 

Exercise as part of your lifestyle may lead to weight loss and help maintain weight loss, especially when combined with a nutritious, balanced diet.

If your goal is weight loss, body fat reduction, and weight maintenance, exercising is an excellent way to reach that goal. Resistance exercise, in particular, can reduce muscle loss and subsequent metabolism slow down that can occur during weight loss.

If you are trying to lose weight but the scale is not moving as much as you’d hoped, keep in mind that you could be losing body fat while preserving or even gaining lean muscle mass. This effect is called body recomposition, and most often occurs in those new to weight lifting, although it may be possible for trained individuals as well, so long as protein intake is high enough.

This article was taken from:

How Many Times a Week Should You Exercise? A Comprehensive Guide
How to Lose Belly Fat: A Scientific Approach
Embracing Fitness After Your 20s: Unlocking Lifelong Energy and Strength
Why Strength Training Can Reduce Chances of Weight Gain During and Post Menopause