Have you ever cut calories drastically in an attempt to lose weight quickly? I did that repeatedly in my teens, and it never turned out well; I felt hungry and miserable while I was dieting and ended up gaining back all the weight I lost because my appetite was out of control. The promise of rapid weight loss is enticing, particularly for people who have a significant amount to lose. But are the consequences worth it?
In a recent small study that hasn't yet been published, researchers from the Netherlands looked at body composition changes in people losing weight rapidly on a 500-calorie diet for 5 weeks vs. more gradually on a 1250-calorie diet for 12 weeks. Of the roughly 19 lbs lost on average between both groups, at the end of the study, the 500-calorie group had lost almost 3 times as much lean muscle mass as the 1250-calorie group (3.5 lbs vs. 1.3 lbs, respectively). This isn't surprising, since when caloric needs aren't being met, the body uses protein for energy, and muscle mass is broken down to provide amino acids that are essential for survival. After 4 weeks, the numbers looked a little better, which the study authors attribute to improved hydration and glycogen repletion (No mention of how much water weight was regained), but the 500-calorie group was still down about 2 lbs of muscle mass from where they started.
The results of this study made me think about the very-low-calorie HCG diet, which people follow for 3 to 6 weeks at a time, often in several rounds. First popularized in the 1950's by British endocrinologist ATW Simeons, the diet protocol involves taking injections containing HCG, human chorionic gonadotropin -- a hormone produced by pregnant women and approved for use as a fertility treatment -- and restricting calories to 500 per day. (There are also HCG drops, but apparently they contain negligible quantities of the hormone). HCG purportedly has appetite-supressant properties that make subsisting on such low energy intake bearable, and although studies suggest otherwise, many proponents claim it also increases fat burning and weight loss. The HCG diet fell out of favor years ago when researchers reported that the dramatic weight loss of up to a pound a day was due to starvation-level caloric intake rather than the hormone injections. However, within the past few years, there has been a resurgence in its use (thanks in part to the diet being featured on the Dr. Oz show), particularly among anti-aging doctors.
The HCG Diet: The Basics
In addition to containing very few calories, the HCG diet is extremely low in fat. The original HCG diet menu below specified the following menu every day, although some updated versions allow people to move some of the foods around to different meals:
Tea or coffee in any quantity without sugar. Only one tablespoon of milk allowed in 24 hours. Saccharin or stevia may be used.
1. 100 grams of veal, beef, chicken breast, fresh white fish, lobster, crab, or shrimp. All visible fat must be carefully removed before cooking, and the meat must be weighed raw. It must be boiled or grilled without additional fat. Salmon, eel, tuna, herring, dried or pickled fish are not allowed. The chicken breast must be removed from the bird.
2. One type of vegetable only to be chosen from the following: spinach, chard, chicory, beet-greens, green salad, tomatoes, celery, fennel, onions, red radishes, cucumbers, asparagus, cabbage.
3. One breadstick (grissino) or one Melba toast.
4. An apple, orange, or a handful of strawberries or one-half grapefruit.
The same four choices as lunch (above).
This is what dieters are instructed to eat for 4 weeks straight while undergoing HCG injections. Not much to look forward to at mealtimes, which is probably by design in order to prevent overindulging. Characterizing the diet as unappetizing would be an understatement.
The plan provides roughly 55 grams protein, 50 grams carbohydrate, and 9 grams fat. So the macronutrient percentages are about 44% protein, 40% carbohydrate, and 16% fat. 44% of calories from protein sounds like a lot but isn't in this case, and when calories restricted to 500, the protein will be used for energy rather than preservation of muscle mass anyway. After a 6-week break from the diet (I couldn't find any specific dietary guidelines to follow during this period), those who want to lose additional weight often resume the HCG injections and 500-calorie diet for another 4 to 6 weeks.
A Sustainable Alternative to HCG
Doctors recognize that loss of lean mass results in a lower resting metabolic rate. So why are many anti-aging physicians promoting a diet that will, if anything, accelerate the aging process by causing significant muscle loss and other health problems? Some claim that HCG allows people to burn their own body fat for fuel and prevent muscle breakdown, but there is no evidence for this. Studies going as far back as the 1970s indicate that the weight loss achieved on this diet is due to its very low calorie content rather than the HCG injections. (As an aside, I had to laugh at some of the "benefits" claimed on the HCG Doctors Directory site, such as "Improves one's singing voice." Really? And I would like to see clinical evidence that thyroid and adrenal function improve in people consuming 500 calories a day for weeks at a time.)
On the other hand, we have research suggesting that a carbohydrate-restricted diet with adequate calories and protein preserves muscle mass during weight loss, including an analysis of 87 studies that found greater fat loss and better retention of lean mass at lower carbohydrate and higher protein intakes. In addition, carb restriction tends to increase satiety, and most people report enjoying the diet and the wide variety of foods they can eat every day. Many experience rapid weight loss at the beginning, which typically slows down to a more gradual pace after the first week or two. Another benefit of a well-balanced low-carbohydrate way of eating is its suitability for long-term use, both for weight loss and maintenance.
I understand how difficult it is to lose weight and how rewarding it can be to lose rapidly. But it concerns me that there are doctors prescribing a diet so low in calories and nutrients along with hormone injections that were discredited years ago. Rather than encouraging immediate gratification with claims like "Lose up to 30 pounds in a month," why not recommend a sustainable way of eating that not only promotes safe weight loss but is highly pleasurable as well? Carbohydrate restriction has all of these things going for it, and more. In a nutshell, it doesn't feel like being on a diet, and that's one of the primary reasons it works well for so many people.
1. Stein MR, et al. Ineffectiveness of human chorionic gonadotropin in weight reduction: a double-blind study. Am J Clin Nutr. 1976 Sep;29(9):940-8.
2. Rabe T, et al. Risk-benefit analysis of a HCG 500-kcal reducing diet (cura romana) in females.
Geburtshilfe Frauenheilkd. 1987 May;47(5):297-307.
3. Lijesen GK, et al. The effect of human chorionic gonadotropin (HCG) in the treatment of obesity by means of the Simeons therapy: a criteria-based meta-analysis. Br J Clin Pharmacol Sep 1995; 40(3):237-243
4. Volek JS, et al. Comparison of energy-restricted very-low-carbohydrate and low-fat diets on weight loss and body composition in overweight men and women. Nutr Metab (Lond). 2004 Nov 8;1(1):13
5. Krieger JW, et al. Effects of variation in protein and carbohydrate intake on body mass and composition during energy restriction: a meta-regression. Am J Clin Nutr 83: 260–274, 2006.
Franziska Spritzler, RD, CDE