Well, that's not always the case. My PT has this:
http://www.uottawa.ca/academic/info/...rams/1193.html
Actually she has her masters, so that's 6 years of university learning about anatomy, physiology, nutrition, etc....
As for reasoning, I have been obese in the past and am trying to maintain my current weight. So I am reading "Refuse to Regain" which pushes the paleo diet. The gist of it is that formerly overweight people are hypersenstive to starchy carbs. The more weight you have lost, the more sensitive one is.
The summary to chapter 4 is:
- "S Foods" are sugars and starches. Both result in adding sugar to the bloodstream.
- S Foods are generally newcomers to the human diet and are not essential for health
- In previously overweight people, S Foods trigger hunger and weight gain
- S Foods have an addictive quality
- Avoiding S Foods improve your odds of successful long-term maintenance.