Why Am I Hungry All the Time? 10 Reasons

Feeling hungry is a natural sensation. It’s your body’s way of telling you that you need to eat. But what if you’re feeling hungry all the time? 

Here, we outline some common reasons why you might feel hungry all the time. They include what you eat, how you eat, and lifestyle factors such as sleep and exercise. 

We’ll also look at steps you can take to feel less hungry.

1. Not eating enough fiber

Fiber works in different ways to keep hunger in check. For example, some types of fiber can hold a lot of water and form a gel when they reach the gut. 

This can slow food digestion and nutrient absorption in the small intestine. Fiber might also cause food to stay in the stomach longer. Together, these may help you feel fuller for longer. 

Also, when fiber is fermented by your gut bacteria, they release beneficial compounds called short-chain fatty acids. These may influence the release of appetite hormones that make you feel full. 

Did you know that chewing can also release appetite hormones? Fiber-rich foods may require more chewing, reducing feelings of hunger by releasing these hormones.

Fiber is present in all plant-based foods, including fruit, vegetables, beans, legumes, nuts, seeds, and whole grains.

At ZOE, we know the importance of a fiber-rich diet. Fiber is the primary food for your gut bacteria — the trillions of bugs in your gut. Your gut microbiome is unique to you and important for good health.

With ZOE’s at-home test, we can tell you which “good” and “bad” bugs live in your gut. We’ll also provide tailored nutrition advice so that you can eat the best foods for your gut health.

To get started, take our free quiz now.

2. Not eating enough protein

Scientists have shown that protein reduces appetite. This is because when you eat protein-rich foods, they suppress hunger hormones like ghrelin and prompt feelings of fullness.

Protein-rich foods include eggs, beans and legumes, nuts, tofu, dairy, meat, and fish.

If you’re not consuming enough protein, you may feel hungry more frequently.

However, most people in industrialized countries consume enough protein daily. 

3. Eating too many refined carbs

During processing, refined carbs lose their fiber. This means the body digests and absorbs them very quickly. 

When you rapidly digest and absorb food, it can lead to spikes in blood sugar levels, which trigger an immediate release of insulin, a hormone that moves glucose into cells. 

Insulin causes blood glucose levels to fall, which signals the release of appetite hormones that can make you feel hungry. 

Our own research shows that if blood sugar levels dipped below their baseline, people reported a 9% increase in hunger and ate over 300 kcal more that day than others whose blood sugar levels didn’t dip.

Try replacing refined carbs, such as white bread and white rice, with unrefined carbs, like brown rice, oats, barley, or rye. 

4. Not sleeping enough

Sleep plays a key role in regulating appetite, so getting enough good quality sleep is important in appetite control. 

If you aren’t getting enough sleep, it can trigger the release of hormones involved in hunger and appetite, such as ghrelin and leptin. 

One analysis of 11 studies found that people who were partially sleep deprived ate 385 kilocalories (kcals) more each day than those who got adequate sleep. Also, the longer you’re awake, the more opportunities you have to eat.

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5. You’re stressed

If you continuously feel stressed, it can increase your appetite. This is because stress raises your levels of cortisol, which can make you feel hungry.

Eating when stressed is often impulsive. Studies have shown that frequent stress increases people’s appetite and influences their food choices. 

For example, people with higher levels of continued stress tend to prefer nutrient-dense high-calorie foods. 

6. Not eating enough fats

In addition to fiber, fat may also play a part in how hungry you feel. 

Fat can delay food from leaving the stomach and going into the intestines, which means it may reduce your appetite. However, the research to date is mixed. 

At ZOE, we know that everyone responds differently to foods. When two people eat the same meal, their blood fat responses can be very different. 

After eating, it’s normal for blood fat levels to rise, but if they stay high for too long, it’s not good for your health over the long run.

When you join ZOE, our at-home test can assess your responses to food, helping you eat the best foods for your body.

7. Not drinking enough water

It’s common to mistake feelings of thirst for feelings of hunger. Drinking water regularly throughout the day may potentially curb hunger pangs by reducing your appetite.

One study reported that people who drank 568 milliliters (2.4 cups) of water before a meal reduced their calorie intake by over 500 kcals. 

This might be because fluids help you feel full, but scientists don’t know exactly why drinking water affects hunger. 

8. You exercise a lot

If you exercise regularly, you may notice changes in your appetite and increased feelings of hunger. These changes will be more obvious if you do high-intensity exercise or stay active for long periods. 

However, changes in hunger due to exercise tend to vary between people. A systematic review including 103 studies reported no consistent evidence that exercise affected energy intake.  

9. Drinking too much alcohol

Although we don’t often think of alcohol as an energy source, it provides 7 kcal per gram of alcohol. It’s more energy-dense than carbohydrates or protein.

Drinking too much alcohol increases feelings of hunger. Why this happens is unclear, but experts suggest that several mechanisms are involved. 

As well as encouraging short-term food consumption, drinking too much alcohol may change levels of appetite hormones and neurotransmitters.

These changes may make you feel hungrier. 

One study showed that men who drank 4 units of alcohol before lunch consumed more high-fat, salty foods and had an overall higher calorie intake than those who drank 1 unit of alcohol. 

10. Medical conditions

Certain medical conditions may cause you to feel hungrier than usual. 

These include endocrine disorders such as type 1 and type 2 diabetes, hyperthyroidism, and Graves’ disease. In addition, anecdotally, there have been some reports of increases in hunger following COVID-19. 

Some medications may also increase feelings of hunger, including steroids and some antidepressants.

What is hunger?

When you think of hunger, images may spring to mind of a rumbling stomach, a feeling of emptiness, and other symptoms such as tiredness, irritability, and moodiness. This is called physical hunger. 

But hunger is a deep-rooted biological process that tells your body it needs food to maintain energy levels. 

It involves complex interactions between hormones that regulate appetite. These hormones are released from the gut and signal to the brain if you’re hungry or full. 

Psychological hunger is driven by an emotional response to food without the physical signs of hunger. It usually comes on suddenly and often involves cravings for specific foods.

Many of the reasons for feeling hungry all the time point to not eating the best foods for your body.

With the ZOE program, you get personalized nutrition advice to help you find what foods work best for you. 

Over 80% of people who closely followed their personalized ZOE plan for 3 months said that they felt less hungry and had more energy.

Summary

There are many reasons why you might feel hungry all the time. You might not be including enough fiber, protein, or water in your diet. 

Or it could be that you’re eating a lot of refined carbs or drinking a lot of alcohol. 

Lifestyle habits can also lead to feelings of hunger, including not sleeping enough, high stress levels, and exercising a lot.   

If you’re feeling hungry all the time, it may be helpful to take a closer look at your diet and lifestyle. There may be changes you can make to help you feel fuller for longer. 

Speak with your doctor if you’re concerned that a medical condition is causing you to feel hungry all the time. 

Sources

A Smartphone App Reveals Erratic Diurnal Eating Patterns in Humans that Can Be Modulated for Health Benefits. Cell Metabolism. (2015). https://www.cell.com/cell-metabolism/fulltext/S1550-4131(15)00462-3

Agrp neuron activity is required for alcohol-induced overeating. Nature Communications. (2017). https://www.nature.com/articles/ncomms14014

Alcohol, appetite and energy balance: Is alcohol intake a risk factor for obesity? Physiology and Behaviour. (2010). https://www.sciencedirect.com/science/article/abs/pii/S0031938410000259

Antidepressant Medications and Weight Change: A Narrative Review. Obesity. (2020). https://onlinelibrary.wiley.com/doi/abs/10.1002/oby.22969

Associations of short sleep duration with appetite-regulating hormones and adipokines: A systematic review and meta-analysis. Obesity Reviews. (2020). https://onlinelibrary.wiley.com/doi/abs/10.1111/obr.13051

Does increased exercise or physical activity alter ad-libitum daily energy intake or macronutrient composition in healthy adults? A systematic review. PLOS One. (2014). https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3893086/

Dose-dependent effects of alcohol on appetite and food intake. Physiology and Behaviour. (2004). https://pubmed.ncbi.nlm.nih.gov/15059684/

Effect of alcohol consumption on food energy intake: a systematic review and meta-analysis. British Journal of Nutrition. (2019). https://pubmed.ncbi.nlm.nih.gov/30630543/ 

Effects of chewing on appetite, food intake and gut hormones: A systematic review and meta-analysis. Physiology and Behaviour. (2015). https://www.sciencedirect.com/science/article/pii/S0031938415300317

Effect of exercise training interventions on energy intake and appetite control in adults with overweight or obesity: A systematic review and meta-analysis. Obesity Reviews. (2021). https://onlinelibrary.wiley.com/doi/full/10.1111/obr.13251

Effects of fat on gastric emptying of and the glycemic, insulin, and incretin responses to a carbohydrate meal in type 2 diabetes. The Journal of Clinical Endocrinology and Metabolism. (2006). https://pubmed.ncbi.nlm.nih.gov/16537685/

Effect of short- and long-term protein consumption on appetite and appetite-regulating gastrointestinal hormones, a systematic review and meta-analysis of randomized controlled trials. Physiology and Behaviour. (2020). https://www.sciencedirect.com/science/article/abs/pii/S0031938420304376

Effect of sleep duration on dietary intake, desire to eat, measures of food intake and metabolic hormones: A systematic review of clinical trials. Clinical Nutrition ESPEN. (2021). https://www.sciencedirect.com/science/article/abs/pii/S2405457721002862

Excessive eating and weight gain: A rare post-acute COVID-19 syndrome. Diabetes and Metabolic Syndrome. (2021). https://pubmed.ncbi.nlm.nih.gov/34438358/

Fat Detection: Taste, Texture, and Post Ingestive Effects. Chapter 15: Fats and Satiety (2010). https://www.ncbi.nlm.nih.gov/books/NBK53550/

Immediate pre-meal water ingestion decreases voluntary food intake in lean young males. European Journal of Nutrition. (2016). https://pubmed.ncbi.nlm.nih.gov/25893719/

Intravenous ghrelin administration increases alcohol craving in alcohol-dependent heavy drinkers: A preliminary investigation. Biological Psychiatry. (2014). https://www.biologicalpsychiatryjournal.com/article/S0006-3223(14)00220-0/fulltext

Neurohormonal Regulation of Appetite and its Relationship with Stress: A Mini Literature Review. Cureus. (2018). https://www.cureus.com/articles/13630-neurohormonal-regulation-of-appetite-and-its-relationship-with-stress-a-mini-literature-review

Population-based assessment of adverse events associated with long-term glucocorticoid use. Arthritis and Rheumatism. (2006). https://pubmed.ncbi.nlm.nih.gov/16739208/ 

Stress-induced obesity and the emotional nervous system. Trends in Endocrinology and Metabolism. (2010). https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2831158/?report=classic 

The effects of partial sleep deprivation on energy balance: a systematic review and meta-analysis. European Journal of Clinical Nutrition. (2017). https://pubmed.ncbi.nlm.nih.gov/27804960/

The glucocorticoid contribution to obesity. The International Journal on the Biology of Stress. (2011). https://www.tandfonline.com/doi/full/10.3109/10253890.2010.534831

The role of protein in weight loss and maintenance. American Journal of Clinical Nutrition. (2015). https://pubmed.ncbi.nlm.nih.gov/25926512/

Understanding the interplay between food structure, intestinal bacterial fermentation and appetite control. Proceedings of the Nutrition Society. (2020). https://www.cambridge.org/core/journals/proceedings-of-the-nutrition-society/article/understanding-the-interplay-between-food-structure-intestinal-bacterial-fermentation-and-appetite-control/7A854AAFAF3B50A2C5FA273157DE4A6D

Unravelling the Effects of Soluble Dietary Fibre Supplementation on Energy Intake and Perceived Satiety in Healthy Adults: Evidence from Systematic Review and Meta-Analysis of Randomised-Controlled Trials. Foods. (2019). https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6352252/

Whole gain intake and glycaemic control in healthy subjects: A Systematic Review and Meta-Analysis of Randomized Controlled Trials. Nutrients. (2017). https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5537883/