Does Not Eating Make You Gain Weight?

Medically Reviewed By Jared Meacham, Ph.D., RD, PMP, CSCS

Typically, not eating or eating less doesn’t lead to weight gain. However, restrictive eating may make weight gain more likely by affecting your metabolism and appetite. Irregular eating patterns can affect your metabolism and appetite, making it harder to maintain a moderate weight.

This article discusses how not eating may relate to weight gain and loss and describes safe and effective ways to maintain a moderate weight.

Does not eating make you gain weight? 

A half-eaten slice of frittata sits on a white plate.
Photography by Oleksandr Stalovierov/Stocksy United

Typically, not eating doesn’t make you gain weight. If not eating means you’re in a calorie deficit or you take in less energy from food than your body uses, it may lead to weight loss Trusted Source PubMed Central Highly respected database from the National Institutes of Health Go to source instead.

However, many factors can affect weight. As a result, not eating or restricting your food intake in other ways can indirectly contribute to weight gain. This may depend on the following factors.

Read more about the reasons for not losing weight in a calorie deficit.

Metabolic adaptation

A 2020 research review Trusted Source PubMed Central Highly respected database from the National Institutes of Health Go to source noted that calorie restriction may cause metabolic adaptation, when your metabolic rate slows down to conserve energy. A slower metabolic rate means your body uses fewer calories, making weight maintenance or loss less likely.

A 2017 review Trusted Source PubMed Central Highly respected database from the National Institutes of Health Go to source also suggested that metabolic adaptation may contribute to regaining previously lost weight.

Rebound eating

Rebound eating refers to eating higher quantities of food after a period of restrictive eating.

Some studies show Trusted Source PubMed Central Highly respected database from the National Institutes of Health Go to source that restrictive eating may lead to strong cravings and increased appetite, making weight gain more likely.

However, other studies suggest Trusted Source PubMed Central Highly respected database from the National Institutes of Health Go to source that if restrictive eating does increase cravings, it may only be short-term. Eventually, a sustained calorie restriction may lead to reduced cravings overall.

Severity of food restriction

How severely you restrict your food intake can affect your body’s response.

For example, small, short-term calorie deficits may be less likely Trusted Source PubMed Central Highly respected database from the National Institutes of Health Go to source to lead to metabolic adaptation than larger deficits.

Intermittent fasting may also improve appetite management and metabolism, according to a 2022 review Trusted Source PubMed Central Highly respected database from the National Institutes of Health Go to source . Intermittent fasting is managed calorie restriction, when you don’t eat for a set period each day.

Read more about intermittent fasting, including its safety and effects.

Other factors that affect weight maintenance 

Many people believe that eating fewer calories always leads to weight loss. However, eating habits are just one of many factors that influence weight.

Other factors that contribute to weight gain include Trusted Source National Institute of Child Health and Human Development Governmental authority Go to source :

  • emotional stress
  • genetic disposition
  • limited physical activity
  • socioeconomic disparities, such as difficulty accessing healthcare or nutritious food
  • certain medications
  • various underlying health conditions, such as polycystic ovary syndrome

Learn more about health conditions and medications that can cause weight gain.

How to maintain a moderate weight

Severe food limitations may not be a safe or effective way to maintain a moderate weight or lose body weight.

Instead, you can maintain or reach a moderate weight more healthily Trusted Source Centers for Disease Control and Prevention (CDC) Governmental authority Go to source in the following ways:

  • eating a balanced diet, such as a Mediterranean diet
  • asking a doctor or registered dietitian for personalized nutrition advice, including target calorie intake
  • getting regular physical activity
  • trying to take gradual, manageable steps rather than extreme measures such as avoiding eating
  • getting enough good quality sleep
  • following your doctor’s treatment recommendations for any underlying conditions you have
  • managing stress, such as with meditation or counseling
  • prioritizing nutritious foods such as:
    • whole grains
    • fruits and vegetables
    • lean proteins

The best nutrition and target calorie intake for weight loss and general health can vary widely per person. Always talk with a doctor before making significant changes to your diet or severely restricting your food intake.

Not eating enough can have negative health effects

In severe cases, not eating enough can lead to effects such as Trusted Source PubMed Central Highly respected database from the National Institutes of Health Go to source :

Talk with a doctor for personalized advice about nutrition and weight to reduce the risk of negatively affecting your health.

Summary 

Not eating or calorie deficits often lead to weight loss rather than weight gain.

However, not eating or severely restricting calories can slow your metabolism and increase your appetite. These factors may make weight gain more likely. Not eating can also negatively affect your health.

Talk with a doctor if you have any questions about nutrition and weight loss or gain.

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Medical Reviewer: Jared Meacham, Ph.D., RD, PMP, CSCS
Last Review Date: 2024 Mar 26
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