All primates may regulate how much we eat based on protein intake

A quite interesting dietary finding has been reported this week: American primates such as spider monkeys and Afrasian primates such as ourselves seem to share a key dietary trait, no matter if we are strictly vegetarian or omnivorous: the main goal of our appetite is to reach a daily target of certain optimal protein ammount.

A.M. Felton et al. Protein content of diets dictates the daily energy intake of a free-ranging primate. Behavioural Ecology, 2009.

The authors have found that spider monkeys, who are strictly vegetarian, do not aim for energy or protein maximum intake, as has been argued sometimes, but for an optimal intake of protein. When their diet is richer in proteins they eat less of everything, when it's low in this key component instead they eat much more until they reach the same daily intake of proteins. This behaviour is the same among humans, so the authors conclude that, unless it is a mere coincidence at both extremes of the ape tree, a separate convergent evolution maybe, this pattern must be general for all apes and maybe even a wider fraction of animals.

It had been argued that this pattern among humans had only evolved with Neolithic. But seems it is not the case after all.

A divulgative article can be found at Science Daily.
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Bacterial protein behind overweight

Found at Science Daily: Waste From Gut Bacteria Helps Host Control Weight, Researchers Report.

This new research , led by Dr. M Yansigawa, has found that certain protein generated by gut bacteria makes a big difference on how mice, and presumably humans, process food at the intestines. When present, the protein slows down digestion allowing for a much better absorption of food, while, when absent, digestion goes a lot faster and nutrients are wasted in a much larger ammount.

Obviously absorbing more food has pros and cons, it probably mproves a lot the survival rate when food is scarce but it causes other problems when food is aboundant, specially overweight and obesity. It is common knowledge that there are two exteme types in this aspect: people who can eat all they want and never seem to gain weight, and people who, even when eating little, always tend to be somewhat fatty. It would seem that this bacterial protein is at least one of the reasons in this dychotomy, what may offer in the mid-run new ways of treatment for obesity and also extreme thinness (surely not desirable either).