Understand Why “Drink When You’re Thirsty” Stops Working in Winter

Water is the most abundant substance in the human body, accounting for approximately 50–60% of adult body weight, yet hydration remains one of the most commonly overlooked foundations of health. Even mild dehydration can negatively affect physical performance, cognitive function, digestion, skin health, and cellular processes. While hydration is often associated with hot weather and exercise, maintaining adequate fluid intake year-round is essential for optimal health (Popkin et al., 2010)..

Hydration and Energy Levels

One of the earliest and most noticeable effects of inadequate hydration is fatigue. Research shows that mild dehydration - defined as a loss of just 1–2% of body water - can impair concentration, alertness, and mood, while increasing perceptions of tiredness and effort (Ganio et al., 2011). This occurs because reduced fluid levels lead to decreased blood volume, meaning the heart must work harder to deliver oxygen and nutrients to tissues. The brain is particularly sensitive to changes in hydration status, which helps explain why dehydration is commonly linked to headaches, brain fog, and reduced mental performance.

Hydration and Digestion

Adequate hydration plays a critical role in digestive health. Water is required for saliva production, gastric secretions, and the efficient movement of food through the gastrointestinal tract. Insufficient fluid intake can slow digestion and is strongly associated with constipation, as the colon absorbs more water from stool when the body is dehydrated (Popkin et al., 2010). Hydration also supports the breakdown and absorption of nutrients, helping digestive enzymes function effectively and ensuring vitamins and minerals are transported throughout the body.

Hydration and Skin Health

Skin is often viewed as an external indicator of hydration status. While increasing water intake is not a standalone solution for skin conditions, hydration does play an important role in maintaining skin elasticity, barrier function, and circulation. Dehydrated skin is more prone to dryness, irritation, and a dull appearance. At a cellular level, adequate hydration helps maintain cell volume and function, contributing to tissue repair and resilience (Palma et al., 2015). Internal hydration provides a foundational support for skin health alongside topical skincare and nutrition.

Cellular Health and Metabolic Function

At the most fundamental level, water is essential for cellular health. Every cell relies on water to maintain structure, transport nutrients, remove waste products, and support biochemical reactions. Hydration influences electrolyte balance, temperature regulation, kidney function, and metabolic efficiency. Chronic low-level dehydration has been associated with increased strain on the kidneys and impaired physiological regulation, particularly when fluid intake consistently falls below needs (EFSA Panel on Dietetic Products, Nutrition and Allergies, 2010).

Hydration in Winter: An Overlooked Challenge

During colder months, thirst cues are often blunted, and people tend to drink less water despite ongoing fluid requirements. Indoor heating, increased respiratory water loss, and continued physical activity mean dehydration can still occur in winter. Hot drinks may replace cold water, but many caffeinated beverages can have a mild diuretic effect, making intentional hydration even more important.

Three Top Tips to Drink More Water in Winter

1. Warm It Up
   If cold water is unappealing, opt for warm water or herbal teas. Warm fluids are just as hydrating and often easier to consume consistently in colder weather.
2. Anchor Hydration to Daily Habits
   Pair drinking water with existing routines, such as having a glass on waking, with meals, and after bathroom breaks. Habit-stacking reduces reliance on thirst alone.
3. Eat Your Water
   Include water-rich foods such as soups, stews, fruits, and vegetables. These contribute meaningfully to total fluid intake while also providing essential micronutrients.

Hydration is not about perfection, but about small, consistent behaviours that support your body every day. By making hydration easier and more intentional, especially during the winter months, you support your energy, digestion, skin health, and cellular function from the inside out.

Which hydration strategy are you going to try first?

References 

EFSA Panel on Dietetic Products, Nutrition and Allergies. (2010). Scientific opinion on dietary reference values for water. EFSA Journal, 8(3), 1459. 

Ganio, M. S., Armstrong, L. E., Casa, D. J., McDermott, B. P., Lee, E. C., Yamamoto, L. M., … Lieberman, H. R. (2011). Mild dehydration impairs cognitive performance and mood of men. British Journal of Nutrition, 106(10), 1535–1543. 

Palma, L., Marques, L. T., Bujan, J., & Rodrigues, L. M. (2015). Dietary water affects human skin hydration and biomechanics. Clinical, Cosmetic and Investigational Dermatology, 8, 413–421. 

Popkin, B. M., D’Anci, K. E., & Rosenberg, I. H. (2010). Water, hydration, and health. Nutrition Reviews, 68(8), 439–458.