I stumbled across this article about a carbohydrate-restriction study while looking for something else.
British researchers took 88 women considered at high risk for breast cancer and divided them into three diet groups. One group adopted a Mediterranean-type diet with a limit of 1500 calories per day. The second group was told to restrict carbohydrates to below 50 grams two days per week, then eat normally on the other days. The third group was also told to restrict carbohydrates to below 50 grams two days per week, but also to limit calories to 650 on those two days.
Here were the results, according to the article:
At the end of four weeks women in both of the intermittent dieting groups had lost more weight — about 9 pounds — than the women who ate low calorie meals every day of the week — about 5 pounds.
Women in the intermittent dieting groups also had better improvement than daily dieters in the levels of hormones — insulin and leptin — that have been linked with breast cancer risk.
Notice that the women who restricted calories every day lost the least amount of weight on average. I couldn’t find a full paper on this study – the article mentions a presentation, so maybe there is no full study published – so we don’t know if they measured changes in metabolism. We also don’t know if the women who went low-carb twice per week reduced their calorie intake spontaneously. All we know is that the women who restricted calories every day lost less weight than those who merely restricted carbohydrates two days per week.
I also found it interesting that both groups of women who restricted carbohydrates lost about the same amount of weight, even though one group restricted calories to 650 two days per week and the other group didn’t. We’ve seen this happen in several studies now: people who restrict carbohydrates lose as much or more weight than people who restrict calories, even though the low-carbers don’t restrict calories and are told to eat to satiety.
If you restrict calories enough and can endure being perpetually hungry, you will lose weight. Nobody disputes that. But there’s a good chance you’ll also end up with a slower metabolism and be miserable much of the time. No thanks. Not when can I keep my weight down just by avoiding sugar and limiting starch. I’m never miserable while eating bacon, steaks, ribs, shrimp, chicken, eggs and butter.
I know what I ate today (scrambled ham and eggs with onions and cheese for breakfast, Italian sausages and mashed cauliflower loaded with butter and sour cream for dinner), but I don’t know how many calories I consumed today … or yesterday, or the day before, or the day before, or on any day in recent memory. And I like it that way.