This statement is a general statement that isn’t always true. Men can certainly lose weight easier in a lot of cases because men typically have more of the testosterone hormone which has an effect on how much muscle a person has. Muscle is metabolically active and burns fat. Women on the other hand have more estrogen hormones and naturally carry more fat on their bodies. Fat is inert and doesn’t burn calories. Women need more fat as it is necessary for having children. Because women’s bodies can often have more fat than men’s, many women have a couple more hurdles to face before we even discuss nutrition, exercise, sleep, time of day eating etc.
Of course there are exceptions as some men tend to have a more endomorphic Healthy Body type (higher percentage of Healthy Body fat percentage than average) while some women have ectomorphic frames (lower percentage of Healthy Body fat percentage than average) and vice versa.
Mesomorphs are in the middle. They tend to carry a lot of muscle. And because muscle is metabolically active the women and men who are mesomorphs may have an increased ability to lose weight due to the amount of metabolically active musculature burning all of those calories that the other groups are lacking.
At the end of the day we work with what we have. Whether we are an endomorphs mesomorphs or ectomorphs woman or man. The one constant is that we age and as we get older our hormone production changes, our activity level changes, our muscle to fat ratio often changes and it becomes more difficult to maintain and or lose weight. If we aren’t exercising regularly and consuming a nutritionally sound it is very common for men and women to gain weight.
So, maintain a daily physically active lifestyle, eat your vegetables, legumes, beans and whole grains. Avoid processed foods, consume healthy non-processed fats and limit your animal protein intake. From there regardless of your gender you will have a pretty healthy base to work from.