In a recent study published in the American Journal of Physiology – Endocrinology and Metabolism, scientists have confirmed that working out while hungry will result in the biggest gains, and is also beneficial to your health in the long-term.
If you eat before hitting the gym, your body will be too busy responding to and digesting the food you've just eaten to focus on burning calories.
This means that exercising straight after a meal is pointless in trying to lose weight in the form of adipose tissue, which is mainly responsible for obesity. Your body instead uses the consumed carbohydrates as energy, resulting in little to no weight loss.
Researchers also believe that going to the gym in a fasted state will result in your body being more equipped to help burn the fat and even turn it into muscle.
Study author Dylan Thompson, from the University of Bath, says: "Adipose tissue is busy responding to the meal [after eating] and a bout of exercise at this time will not stimulate the same changes in adipose tissue."
"This means that exercise in a fasted state might provoke more favourable changes in adipose tissue, and this could be beneficial for health in the long-term."
The researchers studied a group of overweight males and got them to walk for 60 minutes on an empty stomach, then got them to walk another 60 minutes two hours after eating a carb-heavy breakfast.
When the men fasted and exercised, both PDK4 and HSL increased, however they decreased when the men ate before exercise.
Multiple blood and adipose tissue samples taken before and after exercise indicate that working out on an empty stomach burns stored fat, rather than the carbs from a recent meal.
So hold off on that bowl of spag bol until after your workout – your muscles, your waistline and your tastebuds will thank you for it.