The scientists discovered that male mice fed low protein and high carbohydrate diets were more likely to have male offspring with higher levels of anxiety, as measured by time spent in the safety zones of their maze. They also found that male mice that were fed high fat diets were more likely to have daughters with higher levels of body fat and markers of metabolic disease.

“Our study shows that the type of diet eaten before conception can program specific characteristics of the next generation,” says co-senior author and leader of the GECKO consortium Professor Romain Barrès, from the University of Copenhagen and Université Côte d’Azur, Nice.

“It is extraordinary that by titrating mixtures of protein, fat and carbs in the father’s diet we could influence specific features of his sons and daughters health and behaviour. There is some important biology at play here,” said Professor Stephen Simpson, co-senior author and Academic Director of the Charles Perkins Centre at the University of Sydney.

The team also observed that males on a low protein diet also ate more food overall. However, thanks to the study design, they could determine that both the amount of calories, and the macronutrient composition of the males’ diets, influenced the health of their offspring.

“Our study shows that it’s not just eating too much or too little, but the composition of the diet that can have an impact on future children,” says Professor Romain Barrès.

The work was conducted in mice and has opened the way for the team to study the molecular mechanisms involved. The mouse work is part of a broader series of studies within the GECKO consortium, involving humans and other mammals at partner institutions.

“We think our study is a step towards establishing dietary guidelines for fathers to be, with the ultimate goal of lowering the risk of metabolic disease and mood disorders in the next generation,” says Professor Romain Barrès.