Researchers at ETH Zurich in Switzerland have found that harmful effects of a high-fat diet in female mice, such as obesity, insulin resistance and addictive-like behavior are passed on for three generations. The new study showed that second generation offspring — grandchildren of mice that had consumed a high-fat diet, before, during and after pregnancy, showed addictive-like behaviors such as increased sensitivity and preference for drugs, as well as characteristics of obesity, including changes in their metabolism. In third generation offspring (the great grandchildren), differences were observed between males and females, with only females showing addictive-like behaviors and only males showing obesity characteristics.
This was the case although the original female mice themselves never became obese and although none of the following generations consumed a high-fat diet. The investigators studied these effects specifically for transmission via male offspring up until, and including, the third generation. In the study, the researchers fed female mice either high-fat diet or a standard laboratory diet for nine weeks — during the pre-mating, pregnancy and lactation period.
Their male offspring were then mated with females that had been fed a standard laboratory diet to generate the secondgeneration offspring. The male offspring of these mice was again mated with females that had been fed a standard laboratory diet to generate the third-generation offspring. The authors measured body weight, insulin sensitivity, metabolic rates, and blood plasma parameters such as insulin and cholesterol in second and third-generation offspring.
In behavioral experiments they investigated if the mice chose a high-fat over a standard laboratory diet or an alcohol solution over water, as well as their activity levels after exposure to amphetamines. They did this to better understand if a maternal high-fat diet had an effect on obesity, overeating and drug sensitivity in subsequent generations.