1. No. The female's weight during pregnancy is the critical factor in determining whether offspring will be at risk for obesity.
2. No. Healthful eating and regular exercise, not the father's weight, determine whether his children and grandchildren will become overweight.
3. Yes. The sperm of the overweight male increases the risk of obesity in two generations of offsprings.
The correct answer is number 3. Working with test animals, researchers found that "molecular signals in the sperm of obese fathers can lead to obesity and diabetes-like symptoms in two generations of offspring, even though the offspring are eating healthily.
Surprisingly, metabolic disease was seen in the offspring even when the overweight fathers showed no signs of diabetes or metabolic disorders. If these findings are translatable to humans, to give their offspring the best chance for a healthy life, both mother and father need to be trim and fit.