I enjoy reading the blogs written by the many Community members on Atkins.com, as well as the Forums. It gives me valuable insight into what topics are trending and what people are talking about. Recently, there has been a lot of talk about the “Fat Fast” or just plain fasting in general. Community members are recommending them to jumpstart weight loss on Atkins or to overcome a plateau. I am not an expert on fasting, but I can share my own observations from my own experience as well as observations from private practice regarding the Fat Fast.
The Fat Fast is a low-calorie, high-fat program (1,000 calories/day and 80% fat). Dr. Atkins rarely and only recommended this approach with medical supervision in his private practice with severely metabolic resistant individuals for short periods in obese individuals who hit a plateau after months on Induction. However, doing such a low- calorie diet for an extended period of time may wreak havoc with your metabolism. When you follow very a low-calorie diet, your basal metabolic rate will slow down to compensate for the low caloric intake. This is your body's survival response to preserve its internal organs and muscle mass. If you are following the Atkins protocol correctly, you should not be taking in fewer than 1,500 to 1,800 calories daily. This energy supply should not cause a drop in your metabolic rate, but rather maintain the rate and preserve muscle while primarily burning fat (instead of carbohydrate) as a fuel for needed energy.
So I do not recommend the Fat Fast without medical supervision. All it does is shift water balance. You will see the scale move, but as soon as you start eating normally again, the weight will creep back to the same starting point. There are times when the body simply needs a break from weight loss. It has its own system, its own agenda and its own timetable. In the long run, it nearly always responds to sensible management by the person in charge—you. But in the short run, your body may decide to go its own way, for its own reasons, which perhaps we don't understand. The best way to deal with a stall is to wait it out and stick closely to the Atkins Diet protocol. If you are in a later phase of Atkins you can, however, drop back to a lower level of carbohydrate intake to see if that helps, but I would not recommend doing the fat fast. You risk creating a yo-yo dieting scenario.
If you are still in Induction when you hit a plateau, try climbing the carb ladder and add carbs in 5 net carb increments. I know it seem counterintuitive, but it actually works for some people. Once you get up to about 40 net carbs (assuming you are still maintaining and not gaining), then drop back to Induction level again. Sometimes that can work as well, because adding carbs will allow the body to relax a little rather than hold on tight to fat stores.
There was a time, before Atkins, when I was a vegetarian; I was a firm believer in fasting. I would do a vegetable juice fast one week a year, and an intermittent fast (IF) one day a week. I felt great being off all those carbs, and I attributed the well being to fasting and detox. I did, however, lose muscle mass every time, which I did not appreciate since I worked so hard in building it.
Then I got my master’s degree in nutrition, and I began to understand physiology and biochemistry better. What I came to realize is that the feel-good feeling from fasting was actually ketosis, not detox. So I began to do an Induction-type “Paleo” or, as some of you call it, “Primal Atkins” diet, during my experimental “detox" periods, and I never felt better. That was the beginning of my Atkins journey. There I remained, and here I am today 25 years later. There are times when I am too busy to prepare every meal and snack and depend on convenience foods, but then I do my own detox, which is a clean Induction, and I am back to feeling great. No fasting necessary.
As you can see I don't believe the Fat Fast or Intermittent Fasting (IF) is necessary if you are on a fat-burning metabolism. If you don't have a lot of weight to lose, and you are on a good exercise program, just because you are not losing weight, does not mean you are not burning fat. Your body is learning how to burn a new fuel. Once you are keto-adapted, which can take several weeks or several months, depending on the individual, this way of eating will take you to your natural weight. You may stall when you hit a set point, but eventually the scale will start moving again.
Just remember, on Atkins, if you do a very clean whole foods approach, your body will detox, and you will preserve muscle. Sure, you may lose a little weight on an IF, but it is mainly the shift in water balance. Once you start eating food again, the pounds will come back. With all this being said, although I don’t advocate fasting as a weight-loss technique, it is certainly acceptable if you are doing it for religious reasons. It is also acceptable to eat nothing after dinner and get a 12-hour fast in every night to give the digestion a break. Nothing wrong with that as long as you are meeting calorie requirements during the day.
Don’t forget loss of pounds is not the only way to measure success. Look at the other markers. Are you feeling better than you used to? Do you have the energy to do things you want to do? If so, then something is happening to your body. Do your clothes feel loser? Have you tried on those clothes that “felt a little too tight” just a few weeks ago? I hope you've followed my advice about measuring your chest, waist, hips, thighs and upper arms. If you're losing inches, the scale will eventually catch up.
If you are struggling with a weight-loss plateau on Atkins, check out this blog I wrote previously on the topic: