Those who consume fewer calories during flu season could have a harder time fighting off the flu virus.

A recent study showed that mice with a calorie-restricted diet were more likely to die during the first few days of infection than mice with a normal diet.

Both regularly fed mice and calorically restricted mice exposed to the virus exhibited decreased food intake as they tried to fight off the infection. However, the mice on calorically restricted diets took longer to recover and exhibited increased mortality, weight loss and other negative effects. The mice consuming normal amounts of food had their appetites back sooner and recovered faster.