Do People Tend to Eat Less in the Summer?

January 10, 2026 •

6 min read

According to one 2015 study, participants consumed 99.5 fewer kilocalories in a warm office environment compared to a cooler one, suggesting that rising temperatures can influence food intake. This confirms the common observation that people tend to eat less in the summer, and that this is not just a coincidence, but a natural physiological adaptation.

Quick Summary

The sensation of having a reduced appetite in the heat is a real biological response driven by the body's need to avoid overheating. Thermoregulation, hormonal changes, and altered blood flow to the digestive system all play a role in suppressing hunger when temperatures rise, favoring lighter foods and increased fluid intake. This is not necessarily unhealthy, as long as proper nutrition is maintained.

Key Points

Thermoregulation is the primary cause: The body's need to avoid overheating is the main driver behind decreased summer appetite, as digestion is a heat-producing process.
Hormonal shifts regulate hunger: High temperatures can suppress the hunger-stimulating hormone ghrelin and increase the fullness-signaling hormone leptin, reducing overall appetite.
Hydration fills you up: Increased fluid intake and consuming water-rich foods during hot weather can contribute to feelings of fullness and can be confused with thirst.
Digestion slows down in heat: Blood is diverted from the digestive system to the skin's surface for cooling, which slows down digestion and can make large meals feel heavy.
Metabolic rate may decrease: Studies suggest that the body's resting metabolic rate can be lower in the summer compared to winter, requiring less energy from food to maintain temperature.
Lighter foods are biologically favored: Cravings for cool, hydrating foods like salads and fruits are a biological adaptation to reduce the thermic effect of food (heat generated by digestion).
Nutrient balance is crucial: Relying on sugary treats for quick energy can lead to blood sugar issues and nutrient deficiencies. Prioritizing smaller, balanced meals is healthier.

The Science of Summer Appetite: How Your Body Adapts to the Heat

As temperatures climb, many people notice their appetite decreases. The thought of a heavy, hot meal becomes unappealing, replaced by cravings for lighter, more hydrating fare like salads and fruit. This shift in eating habits is not a conscious choice for most people, but a sophisticated physiological strategy controlled by the body’s internal systems. Understanding why people tend to eat less in the summer involves exploring the principles of thermoregulation, hormonal shifts, and changes in digestion.

Thermoregulation and the Thermic Effect of Food

The primary reason for a suppressed appetite in hot weather is the body's effort to maintain its core temperature. This process is known as thermoregulation. Every time you eat and digest food, your body generates heat. This phenomenon is called the thermic effect of food (TEF) or diet-induced thermogenesis. In colder weather, this extra heat is welcome and helps keep you warm. In summer, however, the body is already working hard to stay cool through sweating and blood vessel dilation, so generating additional heat through digestion is counterproductive.

To counteract this, the brain's hypothalamus, which controls both temperature and hunger, signals a reduced desire for food. This is especially true for foods with a high thermic effect, such as protein and fat, which generate more internal heat during digestion than carbohydrates. This biological imperative is why a cold, watery snack feels more refreshing than a heavy, protein-rich steak on a hot day. Studies on soldiers in different climates have historically shown a significant reduction in calorie intake for those stationed in tropical regions compared to arctic ones.

Hormonal and Digestive Adjustments

Beyond the thermic effect, your body employs several other internal mechanisms to manage appetite in the heat. Hormones, hydration levels, and digestive processes all adapt to the seasonal change.

Hormonal Shifts: Higher ambient temperatures can affect the balance of hunger-related hormones. Research suggests that high temperatures may suppress the production of ghrelin, the gut hormone that stimulates hunger. At the same time, leptin, the hormone that signals fullness, might become more active. This hormonal shift helps reduce hunger cues and contributes to a feeling of early satiety.
Hydration and Satiety: When it's hot, the body naturally prioritizes hydration. Increased fluid intake, whether from drinking water or consuming water-rich foods, can contribute to a feeling of fullness. Dehydration itself can also play a role in reducing appetite. When you become dehydrated, your digestive processes slow down, which can lead to feelings of nausea and a general lack of hunger. Your body may even confuse thirst for hunger, making increased fluid intake a key factor in seasonal eating changes.
Redirected Blood Flow: In high temperatures, your body redirects blood flow to the skin's surface to facilitate cooling through sweating. This means less blood is available for the digestive system, slowing down the process and making the stomach feel full faster. This is another reason a large meal can feel uncomfortable and heavy on a hot day.

Winter vs. Summer Eating Habits: A Comparison


Factor	Winter Eating Habits	Summer Eating Habits
Appetite	Generally higher; body seeks fuel to produce heat.	Generally lower; body seeks to minimize heat production.
Food Preferences	Craves hot, heavy, calorie-dense foods (e.g., stews, casseroles).	Prefers cold, light, hydrating foods (e.g., salads, fruits, smoothies).
Calorie Intake	Tends to be higher to support increased metabolic rate for warmth.	Tends to be lower, a natural response to temperature regulation.
Metabolic Rate	Resting metabolic rate (RMR) can be higher as the body expends energy to stay warm.	RMR can decrease as the body requires less energy for thermoregulation.
Hydration Focus	Often less emphasized, leading to potential dehydration.	Highly prioritized, often leading to increased fluid and water-rich food intake.

The Impact of Lifestyle and Food Choices

While biology plays a significant role, lifestyle and food choices also influence summer appetite. The availability of fresh, light produce like berries, watermelon, and cucumber naturally aligns with the body's needs for hydration and lower-calorie intake. The preference for outdoor activities in warmer weather can also influence eating patterns. The desire for lighter meals and fresh, seasonal foods is a healthy way to work with your body’s natural rhythm.

However, there is a potential downside to be aware of. When appetite is low, some people might be tempted to replace nutritious meals with sugary, less-filling snacks and treats like ice cream and sweetened drinks. While these offer immediate cooling relief, they can cause blood sugar spikes and crashes, leaving you sluggish and ultimately craving more sugar. This can lead to imbalances in nutrient intake. Prioritizing smaller, more frequent, and nutrient-dense meals is a better strategy for maintaining energy levels.

Conclusion: Adapting to the Season is Key

The tendency to eat less in the summer is a well-documented physiological response driven by the body's need for thermoregulation. The suppressed appetite, lower metabolic rate, and shift toward lighter, more hydrating foods are all part of a natural adaptive process. This is not a cause for concern for most people, but rather a sign of biological intelligence. By listening to your body and consciously making healthy, hydrating food choices, you can stay nourished and energetic throughout the warmer months. Being mindful of replacing calories lost from skipped meals with nutrient-poor snacks is crucial for maintaining a balanced diet and overall well-being.

Keypoints

Thermoregulation Drives Appetite: The body's need to maintain a stable internal temperature in hot weather is the main reason for a decreased appetite, as digestion produces heat.
Hormones Influence Hunger: Higher ambient temperatures can suppress the hunger-stimulating hormone ghrelin and activate the fullness-signaling hormone leptin.
Hydration Affects Satiety: Increased fluid intake and the consumption of water-rich foods contribute to a feeling of fullness, which can dull hunger signals.
Digestion Slows Down: Blood flow is redirected to the skin for cooling, resulting in less blood for the digestive system and making it harder to process large meals.
Lighter Foods are Preferred: The body naturally craves foods with a lower thermic effect, such as fruits and vegetables, which are typically eaten cold and offer better hydration.
Nutrient Balance is Important: Relying on sugary treats instead of balanced, light meals can lead to nutrient deficiencies and blood sugar imbalances.

FAQs

Q: Why do I have a reduced appetite during a heatwave? A: Your body is prioritizing thermoregulation to stay cool, and since digestion produces heat, it naturally suppresses your appetite for heavy, calorie-dense foods.

Q: Is it bad to eat less in the summer? A: Not necessarily. It's a natural biological response. However, it's important to still consume nutritious, balanced meals to avoid nutrient deficiencies and relying on less healthy snacks.

Q: How does dehydration impact my summer appetite? A: Dehydration can slow down your gut function and make you feel nauseous, both of which can suppress your desire to eat. Staying hydrated is critical to maintaining a healthy digestive system.

Q: Does eating protein in the summer make you feel hotter? A: Yes, to a degree. Protein has a higher thermic effect of food (TEF) compared to carbohydrates or fat, meaning it generates more heat during digestion. This is why you may prefer lighter meals in hot weather.

Q: What are the best foods to eat when you don't feel hungry? A: Focus on hydrating foods like fruits (watermelon, berries), vegetables (cucumbers, lettuce), and chilled soups. Smoothies and yogurt are also great options for providing nutrients without a heavy, full feeling.

Q: Why do I crave ice cream when it's hot but not a heavy dessert? A: Your body craves the immediate cooling effect of the ice cream's temperature, even though the calories from the sugar will eventually produce heat. This desire for instant relief overrides the aversion to a heavy, caloric meal.

Q: Is there a change in my metabolism during summer? A: Yes. Research indicates that the body's resting metabolic rate can decrease in the summer compared to the winter, as it no longer needs to expend as much energy to stay warm.

Citations

heart.org. (2024, June 26). As summer heat cranks up, our appetites may cool off. https://www.heart.org/en/news/2024/06/26/as-summer-heat-cranks-up-our-appetites-may-cool-off MDPI. (2022, January 24). Relationship between Seasonal Changes in Food Intake and Resting Metabolic Rate, Physical Activity, Body Composition, and Depression in Young Women. https://www.mdpi.com/2072-6643/14/3/506 The Quint. (2022, June 2). This Is Why You Don't Feel Hungry In The Summer. https://www.youtube.com/watch?v=lSTP8MXouos naturalnutritionclinic.com. (2025, August 1). Why we eat less in summer and the hidden risk. https://naturalnutritionclinic.com/why-we-eat-less-in-summer-and-the-hidden-risk/ frontiersin.org. (2015, August 24). Warm Ambient Temperature Decreases Food Intake in a Simulated Office Environment. https://www.frontiersin.org/journals/nutrition/articles/10.3389/fnut.2015.00020/full petitchef.com. (2025, July 8). Why are we less hungry in hot weather? https://en.petitchef.com/articles/why-are-we-less-hungry-in-hot-weather-aid-14341 NCBI. (n.d.). Effects of Heat on Appetite - Nutritional Needs in Hot Environments. https://www.ncbi.nlm.nih.gov/books/NBK236229/

Frequently Asked Questions

Your body is prioritizing thermoregulation to stay cool. Since digestion, particularly of heavy foods, produces internal heat, your body naturally suppresses your appetite to minimize additional heat generation.

A naturally reduced appetite is not necessarily bad, as it is a normal physiological response. However, it is important to ensure you consume enough nutrient-dense foods and fluids to prevent dehydration, fatigue, and potential nutrient deficiencies.

Dehydration can slow down your gut function and trigger feelings of nausea, which naturally suppresses your appetite. Sometimes, the brain can also confuse thirst for hunger, making increased fluid intake a key factor in managing appetite during hot weather.

Yes. Protein has a higher thermic effect of food (TEF) compared to carbohydrates or fat, meaning it generates more heat during digestion. Your body’s natural aversion to this extra heat is why you may crave lighter meals instead of heavy, protein-rich ones.

Focus on hydrating foods like fruits (e.g., watermelon, berries), vegetables (e.g., cucumbers, lettuce), chilled soups, smoothies, and yogurt. These options provide nutrients and fluid without making you feel uncomfortably full.

The craving for ice cream is driven by the immediate cooling sensation it provides. This instant physical relief can override the body’s desire to avoid a heavy, caloric meal, even though the energy from the calories will eventually generate internal heat.

Yes. Research indicates that the body's resting metabolic rate can be lower in the summer compared to the winter. This is because the body no longer needs to expend as much energy to produce heat to stay warm.