Dieting to lose weight is often regarded as a female pursuit and men in general, particularly those of previous generations, were not really interested in why they gain or lose weight.
Most men have a number of advantages over their female counterparts when it comes to basic physiology and gaining weight. The following factors 'protect' the males of our species against gaining weight:
Higher basic metabolic rate (i.e. the amount of energy required to keep the body functioning when at rest, or energy used for physiological processes like breathing, digestion etc.). The male basic metabolic rate is 5% to 10% higher than in women of the same weight and height. The higher basic metabolic rate is attributed to differences in body size and body composition (see next point).
Lower body fat percentage compared to women. The average man has a greater proportion of muscle tissue than the average woman and 50% less body fat. The average man has14% body fat compared to 24% in the average woman.
Higher maximum oxygen consumption or VO2 max than women, because of the above mentioned higher lean muscle mass and lower body fat percentage.
The presence of testosterone, the male hormone, that acts as an anabolic agent to promote increased muscle mass.