Thursday, June 18, 2009
Low-Carb Doesn't Work!
Low-carbers hear it over and over. "I can't get to goal." "Nobody I know has reached goal." "Almost all the low-carb gurus are obese."
There are many reasons for weight loss to slow or stop while low-carbing. Read any of Dr. Atkins' books or follow any of the low-carb websites and you will find lots of possible explanations, including factors like low thyroid function and yeast infections.
Another reason for failure to lose weight and for weight regain on low-carb is seldom mentioned. An example is pictured above--low-carb substitutes for high-carb foods. (The picture is taken from a post about a low-carb sponge cake at Cafe Nilson.) But low-carb substitute foods are still low-carb! Why should they interfere with a low-carb diet?
A 2005 study on binge eating in rats may give some insight. In one experiment, the rats were separated into two groups, food-sated and food-restricted. They were then exposed to several food choices, including normal rat chow and a cereal called "Choc and Crisp" which appears to be a German version of Cocoa Krispies. The food-restricted rats took about three minutes to find the rat chow, and they ate about half a gram of it. By contrast, they found Choc and Crisp in only ten seconds and when they reached it, they ate nearly five grams of it.
As expected, the food-sated rats were not interested in the rat chow. They took about 20 minutes to wander over to it and when they got there, they didn't eat it. However, even though these rats had already eaten until they were full, the food-sated group took one fiftieth of that time (25 seconds) to find the Choc and Crisp, and once they reached it, they ate 3 grams of it, or 60% of the amount the food-restricted rats had consumed.
To confirm these responses, each rat was put on a runway with a food-filled box at the other end. When the goal box contained rat chow, it took the food-sated group about 40 seconds to reach the goal, while the food-deprived ones took about 10 seconds. Not surprising. However, when the goal box contained Choc and Crisp, both groups made the trip in about five seconds, though the food-restricted group was a little faster. One might expect that after the first day, the rats would be less excited about the Choc and Crisp, but the time needed to reach the goal boxes persisted over ten consecutive trial days.
The obvious conclusion is that if you feed pet rats with Cocoa Krispies, they will probably get fat. A less obvious inference might be that if a low-carber is freqently exposed to low-carb versions of very enticing high-carb foods, he or she will probably eat those foods to excess. The rat study indicates that the easy availability of very palatable foods may shut off the body's ability to adjust food intake to match energy expenditure. What happens in a rat does not necessarily happen in a human, but their tendency to eat much more of a very palatable food is definitely something to consider when low-carbers have a hard time reaching or maintaining their goal weight.