More than half of all German adults struggle with being overweight, many of whom have crossed the obesity threshold. This brings all kinds of health problems, and fertility suffers too – more than previously thought. A research group from Denmark encouraged 56 obese men to follow a strict diet, observing sperm count and concentration.
»It was surprising for us«
It took about a year for the sperm concentration to double in the leaner subjects. However, they had to maintain their weight and were not allowed to go back to old paths. The conclusion is clear: the fewer sperm cells, the smaller the chance of successful fertilization. Dieting, on the other hand, increases fertility if there are no other restrictions. Study leader Prof. Signe Torekov says, “It was surprising to us that such a great improvement in sperm quality could be demonstrated in combination with weight loss.” She works at the Novo Nordisk Foundation Center for Basic Metabolic Research.
The subjects were divided into four groups
The participants in the study belonged to the age group of 18 to 65 years, their BMI in the beginning was between 32 and an impressive 43. For eight weeks they ate just 800 kilocalories and lost an average of 16.5 kilos. After another eight weeks, the sperm concentration had increased by 50 percent, the pure sperm count by 40 percent. The study then lasted 52 weeks, during which the men were divided into four groups: one received the GLP-1 analogue for weight management, another had to participate in a sports program and was given medication for this. The third group exercised but received a placebo instead of the analogue, while group four did not exercise and also had to make do with a placebo.
The subjects in the first and last groups maintained their weight, while those in group two lost even more. The fourth group of men gained weight about half the weight they had previously lost. Only groups one to three were able to maintain the increased sperm concentration. However, fertility depends not only on sperm count, but also on their quality. This was not taken into account in the study. Similar research shows that women also become more fertile after losing weight, so diet may be the key to overcoming childlessness. 