How are low carb diets different from other weight loss diets? Well, of course they are lower in starches and sugars. But there is another important factor that separates controlled-carb diets from most other approaches.
Supply Vs Demand
In the more traditional approach to weight loss, the main focus is on rationing calories in one way or another - the diet centers around changing how much you get to eat
. Low carb diets, on the other hand, seem to work at least partly by improving satiety
in other words, changing how much you want to eat
. Another way to look at this (for the economists among us) is focusing on limiting the bodys supply
of food vs limiting the bodys demand
for food. This is something that all the low carb diet authors talk about, in one way or another.
Our Calorie Needs
It is difficult to predict how many calories our bodies will need each day. Activity levels and internal processes such as metabolism fluctuate. There is also quite a lot of variation from person to person in calorie needs for the same activities. Of course, you can imagine that a large person will expend more energy/calories doing a similar activity than a smaller one. But even people of the same size can vary by as much as 20-25% in their calorie expenditure for a given activity.
In general, our energy intake and output are very finely tuned, with lots of different systems within our bodies to regulate appetite and energy loss based on the body's needs. Its obvious why it is important for the body to have a lot of different systems that regulate this. Think of it: a person probably takes in and expends at least a million calories over the course of a decade, and yet for the most part there is not much weight fluctuation, if all is going well physiologically.
How Rationing-Type Diets Can Fail Us
Trying to artificially intervene in this system by simply eating less can work for awhile, but after weight drops more than a few pounds, the body starts to react. People start to experience negative symptoms, including cognitive (food obsession, difficulty concentrating), emotional (irritability, depression), and physical (fatigue) reactions, as well as being just plain hungry. Some people, by sheer force of will, can keep going for fairly long periods, but most eventually lose this battle with their biology.
Working With Our Bodies
An alternative to focusing on strategies for eating less is to focus on helping the body to require less food (using body fat for energy instead). A remarkable thing about studies comparing low carb diets to low calorie diets is that usually the people on the low carb diets lower their calorie consumption spontaneously without really thinking about it. They just seem to be satisfied with less food. There has been a fair amount of speculation about why this should be (it presumably has something to do with insulin
and related hormones), but to me the exact explanation seems less important than the sense of working with
our bodies, by addressing the underlying issues and needs, rather than entering into a war with our appetites. People who respond well to low carb diets tend to experience them this way that their bodies are satisfied, and not continually calling out for food. They feel in tune with their bodies needs in a new way. And that feels mighty good!