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Susan B Roberts

Susan B Roberts Ph.D.


Plateaus: Why They Happen, and How to Get Through Them

Overcoming the dreaded weight-loss plateau.

Today's topic is something that nearly every dieter I have ever met is consumed by: what causes those dreaded plateaus, and how to get through them so you can keep losing weight.

If you read official publications on weight loss, as I do given my job as a professor of nutrition and a diet researcher, it would be easy to get the impression that governments think most overweight people are a bunch of slackers who just need to be more responsible. You are told to follow the guidelines, avoid quick fixes that don't work, eat anything in small amounts, watch calories, limit discretionary foods to certain amounts—and not doing all this is necessarily the cause of weight gain and failure to lose weight. Easy!

The view from dieter's world is completely different. Here, slacking off doesn't enter into it. People are working enormously hard to lose weight and pretty much every experienced dieter has a failed diet or two in their past. They are intimately familiar with the stress and despondency of getting nowhere, and the horror of pounds creeping back on despite good intentions. Perhaps the most compelling topic of all is the dreaded plateau—that weight that you just can't seem to break through when dieting, no matter what you do.

So how to deal with this very real, very tough problem?

First of all the basics. When we talk about plateaus we are talking about weight loss—or rather lack of it—but weight is really just a surrogate for what we truly want, which is fat loss. Unfortunately, weight and fat loss don't run in close parallel, especially at the beginning of a diet when body water balance is altered by the new foods you are eating. Even after you have been dieting a while, weight can go up and down by 3 pounds between one day and the next because of changes in hydration and water balance, and menstrual cycle hormones make water change even more than this in some women. So the 1-2 pounds of fat that is all most people can lose per week is genuinely hard to see in among the noise of daily changes in water weight. This is all true for any diet, but especially for those plans that are much lower in sodium than your regular food or are ketogenic (i.e. less than 50 grams of carb per day), because they can make you temporarily lose as much as 10 pounds of water in the first week, even if fat loss is negligible.

More basics: the only way to lose actual fat is to get calorie intake lower than calorie expenditure. This doesn't mean you simply can simply cut calories any old how and expect to lose weight easily (nobody would be fat if this was true!). As I started to talk about in my previous post, eating hunger-suppressing foods at each meal and snack is an important element of success for most people. But the reason you do that is to make it possible to cut calories, because calories are the bottom line.

And real plateaus do happen. If, say, you cut your calorie intake in half and kept it there, you would lose huge amounts of weight over many months. But eventually, your calorie requirements would decrease because your now-smaller body would require less energy to schlep it around, and so eventually you would plateau because your new smaller body would only need half as many calories as it did originally. However, based on my experience in research studies where we measure calorie requirements and study plateaus, usually true plateaus don't happen for six months or more of dieting. If weight seems to be stuck after two, three, or four weeks of dieting, more probably you lost a lot of water early on that is making it hard to see fat loss, and/or calories have crept up so you are no longer making the cut you think you are.

Here are some questions to help you work out whether your plateau is a real stall or not, and if so how to get through it.

1. Are you sure you have really reached a plateau?
Hopes for rapid weight loss get fed by the sharp decrease in weight you may have seen in the first week or two of dieting and by unscrupulous books and advertising promising you more weight loss than the amount of fat it is possible for the human body to lose. It's an unfortunate fact that the human body maxes out at about 2 pounds of fat loss a week, and that is if you go at dieting really actively. So if you have 20 pounds of real fat to get rid of, it is a job that will take a minimum of 10 weeks, and even successful dieters can take 20 or 30 weeks at a slower but still good pace. Some diets definitely cause faster weight loss, but that's just water loss—either inadvertent or deliberate. The trouble here is that 0.5-2 pounds of real fat loss a week is good success but gets lost in day-to-day weights that go up and down. The solution? Buy-in for the long haul, and then choose one of two good ways to track weight. Either weigh yourself just once a week and not worry unless every two weeks you don't drop at least a pound; or weigh yourself daily, don't fuss about individual ups and downs, and keep an eye on whether your "best" day weighs in less each week—if your best weight keeps going down, all is well.

2. Are you eating more than you think?
This is another really common cause of plateaus. You start your diet with great determination but then over time (especially on really strict plans), you change a few things here and there to make it easier. And maybe you had a dinner out one night with friends, and it turned out they had booked into your favorite Indian - you did your best but know it wasn't perfect. Or work was really busy, and you had a breakfast meeting and a working dinner so couldn't stick exactly to your plan. Every change adds calories, often hundreds of them, and what seems like small things add up surprisingly fast, because good food on the table tricks your brain into thinking you are eating less than you are. The end result is you really are dieting most of the last week, but those few occasions when control slipped took away all forward progress.

The solution? Get demanding and make it work. No question, we have a terrible environment that makes weight control harder. But almost everyone can take more control that they do. The fact that the environment works against you isn't a cause to give in, it is all the more reason for you to take control and not feel apologetic. One of my current Instinct dieters recently spend four days at a vendor show out of town and every night was brought a selection of pizza, tacos, pretzels, soda, and other diet-breakers for dinner each night while she was supporting her product. Her solution? The first night, she simply went hungry and ate things she had brought with her back in her room. The next evenings she took along a healthy low-calorie salmon and steamed veggie dinner she ordered at the hotel restaurant—and arrived back home at the end of the week with her diet intact and weight lower than ever. Another of my dieters with a demanding job and home life carries two apples with her whenever she goes out, and has already lost more weight than she had hoped to lose by next summer. There are so many ways you can prevent exceptions becoming routine, it all starts with thinking ahead and being ready to advocate for yourself, and can be just what it takes to keep weight coming down.

3. Are you using a diet plan that isn't cutting calories enough?
Sometimes premature plateaus are real and happen because you are not cutting calories enough. Women with low calorie requirements (those who are, say, less than 5'4" tall or over 50 years of age) often have to cut calories to 1,200 a day to lose weight effectively, and many diet plans only go down to 1,400 or 1,600. So you do lose weight for a week or two because of the water loss of changing to a low sodium meals, but then weight stalls because calories are just not low enough. I'm not suggesting you go hungry here, but finding a lower calorie plan that is also carefully designed to cut hunger may be what it takes to jump-start weight loss in this case.

If you found this post helpful, please share with everyone you who know who diets. Next time, I will be talking about cravings and how to keep them in line.

I am a professor of nutrition and psychiatry at Tufts University and author of The Instinct Diet.


About the Author

Susan B Roberts

Susan B. Roberts, Ph.D., professor of nutrition and professor of psychiatry at Tufts University, is an expert on nutrition and weight control.