Eat Fat, Grow Thin

But that raised another question. What recent study was Dr. Bernstein referring to that showed that people eating more carbs store more fat?

First, he provided some background on his experiment with the four people he gave 900 extra calories of olive oil a day.

“When I was treating them with olive oil there was a problem of taste,” Dr. Bernstein told me. “What I ended up with that everyone liked was Myers’s dark rum. Why did I pick that? Because I knew alcohol was miscible with oil and was more likely to disguise the flavor. Everyone liked it.

“So we had these people doing this for six months. I couldn’t understand how we got that miraculous result. 900 extra calories a day. No effect on weight.

“I called the head of biochemistry at my medical school who was a friend of mine and who specailized in carbohydrate and fat metabolism. He had no idea, which sort of surprised me, and he asked arround all his buddies in that field. No one had any idea.”

Then, Dr. Bernstein saw an article in a professional journal. “And when he read that, he said to himself, “‘Ah, of course!’ It’s lipoprotein-lipase, also called insulin-sensitive lipase. These enzymes gets turned off by insulin. So if you have high insulin levels you cannot break down fat. Furthermore, we know that insulin is the major fat-building hormone. You can only build it and you can’t break it down if you are on a high carbo diet.”

Unfortunately, Dr. Bernstein didn’t remember just where or when he read that study. So he asked me to search a few years’ worth of Diabetes and Diabetes Care. “I need that article so badly for so many arguments,” he told me.

Being able to help someone who has done so much for people with diabetes as well as to learn something for this article was enough to activate my research gene. Working together, we found the article today.

The April 2000 issue of Diabetes contained the article, “Increase in Fat Oxidation on a High-Fat Diet Is Accompanied by an Increase in Triglyceride-Derived Fatty Acid Oxidation” by Patrick Schrauwen and four of his colleagues.

The Diabetes study investigated the mechanism behind the oxidation – rather than the storage – of fat on a high-fat diet. It suggested that insulin might play a role. But, they concluded, “The mechanism behind the increase in fat oxidation on a high-fat diet is unknown.”

Now, seven years later, thanks to the work of Dr. Bernstein and of Gary Taubes we know that the mechanism is lipoprotein-lipase, which works to oxidize our dietary fat, except when our insulin levels are high.

In his important new book, Good Calories, Bad Calories, Taubes explains how lipoprotein-lipase works. Any cell that uses fatty acids for fuel or stores fatty acids uses it. When a triglyceride-rich lipoprotein passes by in the circulation, the lipoprotein-lipase will grab on, and then break down the triglycerides inside into their component fatty acids. This increases the local concentration of free fatty acids, which flow into the cells, either to be fixed as triglycerides if these cells are fat cells, or oxidized for fuel if they’re not.