What comprises a "normal healthy diet?"
- Intermittent fasting a great boost to fat burning and weight maintenance
- Skipping breakfast makes you gain weight
Now, I know the gist of why intermittent fasting can work. And if you read into the skipping breakfast article with a lot of background info they don't provide you can pretty much tell their measure group was people who skipped breakfast and probably had a shitty habits around diet and excercise as well.
But if I'm just casually trying to figure out what normal and healthy are, here are two articles that present research that come to conclusions that (on the surface) are completely opposed, but neither is technically wrong.
Fat was the cause of all problems. Sugar is the new tobacco. Tobacco was recommended by doctors for energy. Sitting is the new smoking. Standing will kill you. Red meat will give you a heart attack. Omega 3 is essential for a million things. Fish oil pills are, well, snake oil. MCT is the new fish oil. Coconut and palm harvesting contribute to global warming. Brown rice is healthier than white. White rice has a lower glycemic index.
What the heck are we supposed to do?
But you're right to be skeptical in general. Nutrition research is in such scientific wilderness that it's hard to consider any guidance at all reputable in any way.
So it's tough to filter through a wide variety of literature to find the reputable material. I try to focus on meta-analyses that cover a lot of ground by authors I consider reputable (and aren't selling a diet themselves).
There's a meta-analysis from 2014, examining a wide variety of studies of diets (ranging from fad to institutionally recommended). It concluded:
"A diet of minimally processed foods close to nature, predominantly plants, is decisively associated with health promotion and disease prevention."
http://www.annualreviews.org/doi/full/10.1146/annurev-publhe...
Original study:
http://www.annualreviews.org/doi/full/10.1146/annurev-publhe...
I take your logical point about how "don't overeat" begs the question, but this is where Davidson's charity is helpful. The best way to read "not too much"--if you follow Davidson's advice and assume Pollan is rational--would be to read it as a shorthand for something like the following recommendation:
Calibrate how much you eat to avoid obesity, because obesity is correlated with significantly lower health outcomes over the long term.
Caveat, some people should shoot for a BMI < 35, some should shoot for a BMI < 27.5, so precise general advice is probably impossible.
All you have to do is eat a moderate amount, wait twenty or thirty minutes (for your stomach to start digestion, send signals to your brain, etc), see if you are still hungry, and eat a bit more if you are. If you reach the point where you feel 'full' you've probably overeaten. Not complicated, although many people, myself included, don't always take the time to listen to their bodies or have the self control to stop eating when they are chowing down on something delicious, even though know they've probably had enough.