Extreme heat and insulin resistance: a guide to protecting your metabolism in summer
Environmental factors and metabolic health are becoming increasingly closely linked: here’s how to look after yourself through your diet
The heatwaves currently affecting much of the country are not only a risk to the cardiovascular system or to fluid balance. Prolonged high temperatures can also affect metabolism, blood sugar control, appetite and digestive function, particularly in more vulnerable people, such as the elderly, and those with obesity, diabetes, prediabetes, metabolic syndrome or insulin resistance. Prevention, therefore, is essential.
The Golden Rules
Adequate hydration, a balanced diet, physical activity adapted to environmental conditions, good-quality sleep and careful clinical monitoring are simple measures backed by solid scientific evidence. In many cases, they are sufficient to reduce the risk of metabolic imbalance and to maintain long-term health. Substances that curb appetite and reduce the absorption of animal fats can have a beneficial effect on metabolic conditions. The challenge in the coming years will be to integrate climate medicine with preventive medicine, recognising that environmental factors and metabolic health are increasingly closely interlinked.
One in three adults
Today, more than one in three adults has some form of insulin resistance, a condition in which the muscles, liver and adipose tissue become progressively less sensitive to the action of insulin. In the early stages, the pancreas is able to compensate by increasing its production of the hormone. Over time, however, this response becomes insufficient, leading to alterations in blood glucose levels, the accumulation of visceral fat, elevated triglycerides, fatty liver disease and, subsequently, type 2 diabetes and cardiovascular disease. Insulin resistance does not affect glucose metabolism alone. It is a systemic condition characterised by low-grade chronic inflammation, alterations in lipid metabolism, adipose tissue dysfunction and changes in the interaction between the gut, the microbiota, the liver and the endocrine system.
The summer diet
In summer, it is advisable to opt for a diet inspired by the Mediterranean diet, rich in fresh, minimally processed foods with high nutritional density. Seasonal fruit and vegetables provide a source of water, fibre, vitamins, minerals and bioactive compounds. It is advisable to choose whole grains, pulses, fish, extra virgin olive oil and lean protein sources, whilst limiting the consumption of ultra-processed foods, which are high in simple sugars, saturated fats and sodium. Eating moderate-sized meals spread throughout the day reduces the post-prandial metabolic load and promotes better blood glucose control.
During the hottest part of the day, it is best to avoid large or high-fat meals, which place a greater strain on the digestive system. Staying hydrated is one of the most effective ways to protect your metabolism, whilst exercise improves insulin sensitivity even during the summer.
