Where does calorie facts/science come from?
I often hear dire warnings not to go below 1200 calories a day or I'll go into starvation mode, etc.,etc.
Where does that come from?
When people had to forage for food, I highly doubt they were eating 1500+ calories a day, they just ate what they could when they could. No three meals a day, no 1500 calories for women, 2500 calories for men requirements.
Starvation mode is real, but it's not what most people make it out to be. Metabolic adaptation takes long term changes in diet to cause rather minor effects. I'm going to only eat about 500 calories today, not going to be in starvation mode tomorrow. When people hunted and foraged for food, they didn't pick the lean chicken breast option, they ate the fat, offal, and marrow, the calorie-dense parts. Not really necessary nowadays with food in steady supply.
That's a very good question. I'd like to know too. I keep my calories pretty close to that already, but if I eat more, my waist expands quickly.
Another thing is that it makes no sense at all to specify one minimum for men, and one for women. Metabolism can vary greatly for different people, so that means a minimum calorie specification is going to be wrong no matter what number is picked.
We have a natural starvation defense mode built in (reverse T3, or rT3), but you don't want to go there on purpose. I brought this up on several of the IF threads. I'm writing an article about it right now.
A lot of the knowledge we have about caloric restriction was gained from the Minnesota Starvation Experiment, which I recommend reading up on for anyone who is interested about nutrition and weight loss.
Also, keep in mind that just because humans often went hungry during the history of our species, it does not mean that it is optimal for health. Humans are much healthier when they are well-nourished.
The Primal Holla! Eating fat. Getting lean. Being awesome.
You were sick, but now you're well, and there's work to do. - Kilgore Trout
I think this is a really good example of what Mark refers to as Conventional Wisdom. Facts that we all know from somewhere but forget, like Yahoo! news or Men's Health, and then accept into our daily lives. But where's the real evidence? What were the exact specifications of the study, and who performed it? I'd love to know this too so I can judge for myself the validity of it.