How Dietary Choice Influences Sweating and Heat Sensation

Have you ever taken on an eating challenge or been adventurous with food, only to regret it with pangs of hot flashes and a sudden rush of sweat? How did your dietary choice cause sweating and turn up the body heat?

Sweating triggered by food and drink is called gustatory sweating.¹ Sweating of the face, scalp, or neck is commonly caused by hot and spicy food. The food consumed causes increased metabolism, leading to an elevated body temperature and sweating to restore a normal body temperature.¹

This article answers how dietary choices (the food on your plate or cup) influence sweating, a response to increased body heat sensations.

Sweating: All you need to know about the salty liquid

Sweat is the salty, colourless liquid secreted by your sweat glands. The production of sweat and its evaporation from the skin surface is crucial for maintaining the body temperature (around 37 °C or 98.6 °F).^1,2

Sweating is essential for regulating body temperature (thermoregulation), good grip (sweat on hand palms or feet soles), skin hydration, defence against microbes, and the removal of waste and toxins from the body.^1,2 

Explore more on the health benefits of sweating every day.

The science of sweating and heat regulation

Sweating can be in response to a hot environment, heat generated by exercise and food metabolism, and emotions (stress, anxiety, pain, fear, and sexual arousal).¹

Metabolism adds heat to the body

Exercise breaks down stored energy reserves (e.g., glycogen) in the body (mainly in the liver and muscles) to produce energy and heat. In contrast, food metabolism involves breaking nutrients from consumed food into energy and heat.  

The heat generated during metabolism (the body's energy and heat production process), or the metabolic heat, is conserved in the body as a heat reserve or transported to the skin to be released.³

A balanced metabolic heat production, its storage, and its release maintain the body temperature, with blood playing a crucial role.³

Blood, acting as a cooling system, absorbs the excess metabolic heat and distributes it throughout the body. The excess heat is transported to the skin's surface, releasing it into the surrounding air.³

Explore the 3D simulation of skin, the largest organ of the human body. 

Role of sweat glands and sweat in heat dissipation

Sweat-producing sweat glands, found on our body, are of two main types, categorised based on their distribution, location, and sweat composition.^1,2

• Eccrine glands 

These glands are distributed almost on the entire body surface and produce the highest volume of watery sweat.^1,2

Eccrine glands are the only sweat glands found on the hand palms and feet soles.¹

• Apocrine glands

Activated during puberty, these glands are located in specific regions of the body, including the armpit, scalp, and breasts.^1,2

Apocrine glands produce viscous, lipid-rich sweat and release it into the hair follicles and not the skin surface.²

Therefore, the watery sweat of the eccrine glands is released to the skin surface through the skin’s sweat pores. The sweat traps the blood-transported heat on the skin’s surface. When the heat-stored sweat evaporates in the environment, the body cools, regulating its temperature.³

Brain: Body’s thermostat for temperature regulation

The science of sweating and heat regulation would be incomplete if the main player is not explained.

The brain (hypothalamus, to be accurate) keeps track of the body temperature by closely monitoring the temperatures of the flowing blood (core body temperature) and the skin through temperature-sensitive nerves and receptors.³

Any deviation from the default body temperature (around 37 °C or 98.6 °F) due to internal or external factors activates a response to reach the default temperature through various mechanisms.^3,4

The responses involve changes in:^3,4

• Behaviour (e.g., in high temperatures, reduced appetite leads to low food consumption, metabolism and heat generation)
• Blood flow distribution (e.g., in high temperatures, the blood vessels serving the skin widen, increasing blood flow and thus heat loss)
• Metabolic rate (e.g., in high temperatures, metabolic rate reduces by lowering the levels of metabolism-stimulating hormones, thyroid hormones and adrenaline)
• Induction of sweating if heat loss is needed

Signals from the hypothalamus regulate the body temperature by directing the production of chemical messengers, neurotransmitters (acetylcholine), to activate the eccrine glands for watery sweat secretion.¹ 

How dietary choices influence sweating and body temperature

Spicy food, a sugary diet, high-protein food, alcohol, and caffeine are scientifically established to influence heat production and/or sweating through stress response mechanisms, altered Blood flow distribution and metabolic rate, and thermoregulation.^3,4,5 

Some like it hot: How spicy food makes you sweat

Your spicy dietary choices trick your brain into thinking there is a sudden increase in body temperature. This sudden temperature change triggers stress response mechanisms, including sweating and altered metabolism.^1,5

Dietary capsaicin

Bell peppers, jalapeños, and paprika have one thing in common: capsaicin. These capsaicin-containing spices and many more are used worldwide, commonly by Asians, for their hot, spicy, and tangy flavour and health benefits.^5,6

Capsaicin in chilli peppers induces sweating, which many consider a side effect of chilli peppers. However, chilli peppers are a dietary choice for people living in hot climates, for they consider sweating an internal cooling process.⁶

How does capsaicin trigger sweating? When consumed, capsaicin hacks the body's heat sensors (TRPV1 receptors), thereby tricking the body's thermostat (the brain) into sensing an increased body temperature when it hasn't.⁵

The sensation of a heated-up body activates the body's cooling mechanisms, like sweating, making capsaicin a natural air conditioner.^5,7

Read on to understand more of this response.

Black pepper: Does it cool or heat the body?

Pepper, the universal seasoning, is famously paired with salt on tables worldwide—but it brings more than just flavour. In addition to their wide range of health benefits, black peppers, like chilli peppers, warm the body and can cause mild sweating.⁵

Like capsaicin, piperine in black peppers binds to TRPV1 receptors, tricking the body's thermostat.^5,8

To regulate the body’s temperature to default, the hypothalamus directs the adrenal glands to produce catecholamine (e.g., adrenaline) production as a stress response.

Catecholamines, in response to stress, stimulate the metabolism of the energy reserves to produce energy and heat.^5,9 Increased blood flow to muscles and the body makes you feel warm.⁹ In addition, sweating could be experienced. 

For context, remember sweating while stressed or anxious? The catecholamines cause stress-induced sweating by activating the eccrine and apocrine glands. 

Commonly used spices in your pantry have pungent, natural compounds - zingerone and gingerol (ginger), eugenol (nutmeg and clove) - that activate the TRPV1 receptors, inducing sweating and heat sensations, owing to similar response mechanisms.^5,8

Sweet Sweat: Is that even real?

Can dietary sugar lead to sweating? A study involving healthy toddlers (18-20 months old) found night sweats (excessive sweating drenching sleepwear and bedding) as the cause of disrupted sleep due to dietary sugars (e.g., sugar cubes, candy, chocolates) before bed.¹⁰

Consuming large amounts of carbohydrates, especially simple sugars in pastries, sodas, and ice creams, is broken down quickly into glucose. 

To maintain blood glucose levels, rapid insulin is produced in amounts more than required by the pancreas, ultimately leading to a sugar crash or low sugar levels.¹¹

The sudden drop in blood sugar (reactive hypoglycemia) activates the production of catecholamine (adrenaline) to break down glycogen stored in the liver to restore lost glucose in the blood.¹² This adrenaline response contributes to the heat generated and sweating.

Protein-rich diet: Is meat sweat a fact?

You need energy to get your smartphone running. Similarly, your body keeps you alive by burning calories (energy expenditure) to keep your vital organs running. We regain those calories and more from our diet.

The food consumed must be digested; nutrients must be absorbed and metabolised to derive calories from food. Digestion requires energy. The body’s energy reserves kick-start digestion, only to be fuelled by the energy released from the food’s metabolism.

A diet rich in proteins requires more work, or energy, to be broken down as proteins are more complex than carbohydrates and fats.¹³ More work means more heat generated, like an overworked smartphone that heats up.

While a high-protein diet metabolism does increase your body temperature, sweating profusely may be unusual.¹³ Therefore, meat sweats may be a stretch unless you consume excess meat on a hot summer afternoon (to be avoided).

Alcohol: The drink that makes you feel hot and sweaty

While we often 'raise a glass' to feel warm in cold weather, did you know that alcohol can increase your risk of hypothermia?

With increasing blood alcohol levels, the blood flow to the skin also increases due to the widening of blood vessels. However, this warm blood comes from the body’s core (viscera), leading to a lower core temperature.¹⁴

Alcohol metabolism by the liver produces heat; more heat is released from the skin, and core body temperature decreases while the feeling of warmth lingers. Alcohol alters temperature sensation and delays shivering. However, clarity on its effect on thermoregulation lacks sufficient evidence.¹³

Alcohol also causes hypoglycemia. With the liver involved in alcohol metabolism, glucogenesis (metabolism of glycogen) in the liver to restore the lost glucose from an alcohol-caused spike in insulin production takes a back seat.¹⁵ 

Alcohol consumed with glucose accelerates reactive hypoglycemia, with profuse sweating as a common symptom.¹⁵ 

Caffeine and heat: Why it could lead to heat illness?

Caffeine is consumed by 80 % of the world’s population as coffee, tea, energy, and soft drinks.¹⁵

Caffeine also hacks our body’s control system to give you that warm feeling. To clarify, caffeine, by blocking a control button called the adenosine receptor, unveils a series of effects, including sweating and increased core body temperature.¹⁶

Blocking the receptor causes unregulated catecholamine production, leading to:¹⁶

• Decreased skin blood flow, affecting the heat transport to the skin surface and its release 
• High metabolic heat production, increasing the core body temperature due to compromised heat dissipation

Also, acetylcholine (which activates the eccrine glands) production increases, influencing sweating.¹⁶ 

However, the sweat’s cooling effect may be ineffective due to low heat transfer to the skin surface, which, at high caffeine doses (more than 400 milligrams a day) on a hot day, could lead to heat illness.  

Can warm food impact body temperature and sweating?

Your food or drink components can increase body temperature and influence sweating. Drinking warm water - that doesn’t burn your tongue - is the best way to understand the effect of warm food.

Research studying the body’s response to drinking water at different temperatures (room, 3°, and 60°C) found increased body temperature and sweating.¹⁷

The temperature sensors in the oral cavity, pharynx, and larynx detect any temperature change and start the temperature regulation.¹⁷

The effects of diet on body temperature and sweating vary between individuals. Factors like body fat, muscle mass, age, metabolism, hormones, health conditions, and genetics influence sensitivity to heat-inducing foods.

Summary

• Spicy food, a sugary diet, high-protein food, alcohol, and caffeine are scientifically proven to influence heat production and/or sweating
• Spicy food increases body temperature and triggers sweating by tricking the body to turn on its stress response
• Sugary diets and alcohol cause hypoglycemia, leading to profuse sweating
• Alcohol tricks your brain into detecting warmth by driving blood away from the body’s viscera to the skin, risking hypothermia on a cold day
• Caffeine increases sweating and body temperature, risking heat illness when exercising with a higher caffeine dose on a hot day