compare the food habits of earliest people and present people
Answers
Explanation:
Much attention is being given to what people ate in the distant past as a guide to what we should eat today. Advocates of the claimed palaeodiet recommend that we should avoid carbohydrates and load our plates with red meat and fat. Its critics, on the other hand, argue that these are the same ingredients that would set us up for heart attacks. Moreover, these animal-derived foods require more space to produce on our crowded planet filled with starving humans.
A factual foundation for the debate is provided by a review of the eating patterns of early humans and how we adapted to digest starches softened by cooking. The researchers contend that it was digestible starches that provided extra energy needed to fuel the energy needs of bigger brains, rather than extra protein from meat to grow these brains.
But the most striking thing about human diets is just how variable they have been and the adaptations that have taken place. Furthermore, the American evolutionary biologist Marlene Zuk in her book Paleofantasy contends that these dietary adaptations are not fixed on what our ancestors ate in caves at some time in the past.
So are our energy, or protein, needs much different from other mammals of similar size? Brains demand a lot of energy but so does the liver and the digestive tract. The extra nutrition that we need for brain work may be counterbalanced, at least partially, by a lesser need for:
a long gut to process poor quality foods, or
a large liver to handle nasty chemicals in these plant parts.
Once built, a large brain does not require extra sources of protein to maintain its activities.
My studies on the dietary requirements of savanna-inhabiting herbivores highlight how these animals must cope with the dry season when most herbage is brown and indigestible even with the aid of microbial symbionts in the gut.
But carnivores do not have this problem because the dry season is when weakened herbivores are most readily killed, especially when they concentrate around scarce waterholes.