Fasting and Testosterone

Testosterone is important for men’s health and well-being. It also prevents osteoporosis, helps determine how much muscle mass a man will possess, and affects a man’s libido.

As men age, testosterone levels decrease.

Although most sports consider it to be a form of “doping,” and although it’s been banned by the International Olympic Committee, some athletes use testosterone in the form of anabolic steroids to improve performance, build muscle and decrease body fat.

Testosterone can be consumed via intramuscular injections, transdermal gels and patches, and implantable pellets.

Bodybuilders and fitness competitors often use testosterone doping, and it’s largely responsible for the unrealistically large proportions of professionals in these sports.

Testosterone levels can also be changed by workouts, nutrition intake – and even by a man’s mood.

High protein and high fiber diets can decrease testosterone levels, and diets with low protein and higher saturated fat tend to increase levels, but fasting can also affect levels.

Short fasts don’t seem to have an effect on normal testosterone levels. Testosterone levels tend to be highest – 20-30% higher than levels found in the evening – the morning after an overnight fast.

Longer fasts can decrease testosterone levels slightly. By the third straight morning of fasting, morning serum testosterone levels are usually notably reduced [Röjdmark S. 1987], however measurements are still within a normal range for healthy adults [Merck Manual 1992].

With the Eat Stop Eat program, fasting is only maintained for 24-hours, so serum testosterone levels never drop below normal. Eat Stop Eat also requires you to follow a resistance training program, which also increases testosterone levels [Ahtiainen JP, 2004].

With Eat Stop Eat, you can still reduce body fat and build muscle mass without lowering your testosterone levels.