You bring up a good point. I chatted with a missionary in a 3rd world country who was in a village where the people ate the natural foods found and grown there. The women carried heavy water pots on their heads, the men could lift very heavy logs and make strong houses, etc. After about a year or so there, the missionary had introduced American sweets, hamburgers, processed foods, soda pop and more for his own diet and had shared with the village. Cases of food were donated to this 'poor suffering village of lost souls". In no time, the people began to gain weight, their endurance got weaker, their stamina suffered and the people seemed to 'get lazy'. So much for the Western World diet.