by Barbara Berkeley, MD
The weight loss experience comes in two distinct forms: the temporary diet that induces weight loss and the (hopefully) permanent behaviors that lead to weight maintenance. Confusing the two is easy because successful maintainers continue to eat and exercise in a way that looks alot like their original diet. But there is an important difference: maintenance requires achieving balance while dieting requires inducing defecit.
This month, I posted a youtube video (scroll down to find it) that asked the following question: What is a Diet? I was referring to the weight loss portion of diet which I believe is firmly tied to two elements: 1. Recreating an ancient response to famine by consistently limiting calories and 2. Avoiding foods that stimulate insulin (starches and sugars). These beliefs are obvservational and based on my experience with thousands of dieters but they remain hypotheses as they (and most obesity theories) are not confirmed by research.
That's why I was fascinated by an article that appeared in today's Science Daily, a round up of ongoing scientific thought and research. Evolutionary anthropologist Erin Vogel from Rutgers provides thought provoking commentary into the eating habits of orangutans, a species that is closely related to our own. Like humans, orangutans store fat when calories are plentiful. The only time that they burn this fat is during times of significant calorie restriction. Orangutans normally eat alot of fruit, but when it is not available, they survive despite very low protein intakes. They do this by switching to a diet that contains other protein sources and by activating a response that burns their own fat and muscle. In other words, they activate an ancient famine response. This response is obviously meant to be protective and to allow the organism to survive a tough period.
And so it appears to be with humans. We won't lose weight unless we put our body into the same situation that provoked weight loss in ancient times....calorie deprivation. While we don't have to completely starve ourselves, we do need to convince the body that there is an ongoing lack of food, thus activating primal responses and fat burning. What usually scuttles a weight loss diet is periodic "cheating" or inadquately following the plan. (For more, see my previous post on why your diet isn't working.)
Weight maintenance is a different animal. The trick here is to rehabilitate the mechanism, normally automatic but malfunctioning in weight gainers, that decides whether food is burned or stored. The best way to do this is to avoid foods that turn into sugar, including starchy carbs and (in my view) grains. The reason? The axis which appears most broken is the one that partitions sugars for burning or storage. Since we don't need these foods to survive and can get plenty of healthful carbs from fruits and vegetables, it is easiest to avoid this mechanism entirely. That's the basis for the recommendation of Primal, Paleo or Primarian diet. When we look at our closest evolutionary relatives, we have a clear picture of ancient diet. It always pays to consider the thought that we are just a dressed up, modern version of our ancient selves.