Could You Lose a Pound a Week to Save $500? A Guest Post

It is devilishly hard to lose weight.

A randomized control year-long study looked at the impact of four different diets (Atkins, Ornish, Weight Watchers, and Zone Diets) on a group of overweight and obese subjects who were looking to lose weight. The diets produced only “modest” average weight loss of about 6.4 lbs (2.3 percent of original body weight) and found no statistically significant difference in weight loss for the four different diets.

People do a pretty good job of losing weight for about half a year, and then their weight tends to drift back toward their pre-diet number. The difficulty of sustaining weight loss can be seen in this figure taken from a 2-year randomized study of the Weight Watchers program:

Weight lossSource: Stanley Heshka, et al., Weight Loss With Self-help Compared With a Structured Commercial Program: A Randomized Trial, 289 JAMA1792 (2003)

The lower line (marked “Commercial”) shows the average weight loss of the Weight Watchers Diet group, while the upper line (marked “Self-Help”) shows the average weight loss for the control group dieters. In this study, Weight Watchers does produce a statistically significant weight loss (and a loss that is greater than the control group), but it is disappointingly small – the average loss after a year is less than 6.5 lbs. Most overweight people who start a diet want to lose at least 10 percent of their body weight. But only 16 percent of the Weight Watcher’s group (and only 6 percent of control group) lost 10 percent or more of their body weight at the end of two years.

My personal experience with dieting has followed a similar pattern. Like many others, I went from being a skinny twenty-something who couldn’t gain weight to a forty-something who couldn’t keep it off. In the last decade, I’ve yoyo-ed several times. I’d take off a bunch a weight, but by the end of the year I’d put it all back on plus a little extra.

Until this last year, when I did something different. As described in this L.A. Times op-ed, I put $500 each week on safely losing and keeping off my extra weight. You can see what happened in this graph:

weight loss commitment device

I originally had to lose a pound a week (or else lose money). Then I had to keep my weight below my contractual target of 185 pounds.

In contrast to Weight Watchers, which can cost about $500 a year and helps you lose on average 6 or 7 lbs (about 3 percent of your initial weight), I put $500 at risk each week. In equilibrium, I’ve lost 25 pounds (12 percent of my pre-diet body weight) and so far it has cost me nothing.

The rapid weight loss at the beginning of the graph is not remarkable; I’ve lost weight quickly several times before. What’s remarkable is that I kept it off for the second half of the year. And I’ve signed up again this year to do the same thing. You can follow my progress here.

As Levitt has written, I also helped create a Web site called, where you can enter into your own commitment contract to do all kinds of things.

For me, it’s been surprisingly easy — five hundred bucks is a lot of money. And while the prospect of losing 25 pounds is daunting, it’s not that hard to lose a pound a week when the alternative is to lose $500. Indeed, StickK contracts invert the normal commitment problem. Usually it’s easy for people to make New Year’s Resolutions, and much harder for them to live up to them. With StickK, it’s actually relatively easy to keep your commitments – especially if you put enough at risk, or if you designate an anti-charity to get your money if you fail. The harder part is getting yourself to make the binding resolution. Some people are reluctant to enter into a contract that commits them to real change.

Tyler Cowen at Marginal Revolution thinks it’s so hard to get people to change that he has predicted that the site will not succeed:

I’ve long predicted this won’t work; one group of potential customers doesn’t really want to change, the other group is unwilling to give up control. It’s not exaggerating to say that human nature is on the line here, and that if I am wrong this is probably the most important idea you will ever encounter.

But the good news is that the first returns are very positive. In a little more than a month since launching, people have given us $80,000 to help stickK to their goals. What’s more, most people are keeping their commitments and getting their money back.

People who really want to change are willing to give up some of their ex-post freedom. StickK not only helps you make credible commitments for yourself, it also lets you communicate that commitment to other people. Commitment contracts aren’t just for people who have trouble keeping their commitments; they are for anyone who is concerned about hearing some promise that just sounds like so much “cheap talk.” We’ve all been in the “Lucy holding the football for Charlie Brown” situation, where we’ve heard people make promises that we suspect are insincere, or we think the promisor one way or another isn’t likely to follow through. One of the coolest things about StickK is that it gives the rest of us a new way to respond to cheap talk. At last, we can demand that the promisor put some money where his or her mouth is.

Rita: Lovely Meter Maid

Okay, fine. Losing $500.00 is a good motivator to keep losing weight, if it's truly enforceable (making your contract public must help). But...let's see where your weight-loss is in five years. Or ten. Or, hey, even three years from now. Will the weight still be off? Maybe. Twenty-five pounds, while a challenge, is not the same as trying to lose, say, 125 pounds. Which means: I think your "solution" is mainly a gimmick that will not succeed for serious and sustainable weight loss. Which means it's really no different than Weight Watchers and so forth, in terms of overall results. But, at least at WW, they get those cute little ribbons, or whatever it is that is given out for being "good".


With regard to this statement:

" statistically significant difference in weight loss for the four different diets."

Often, "statistical insignificance" just means that the sample size wasn't big enough to say for sure that there was a genuine difference between the factors being tested (in this case, the four diets). I'd be curious to see how much of a difference there actually was between the diets... I'll bet that if the sample size was increased, the means of the data would still hold up (except with a smaller standard error).

Konstantin Monastyrsky

People (and researches) confuse weight loss with fat loss, or, actually, no loss.

In order to consistently lose fat (not just weight) on any diet, you must keep your body in a perpetual state of lipolysis, or what Dr. Atkins used to incorrectly call ketosis.

To accomplish this feat you must consume: (a) ZERO carbs; (b) under 60 grams of protein to prevent muscle wasting, and (c) under 70-80 grams of fat to enjoy some level of satiety, enhance the digestion of proteins, maintain the integrity of intestinal mucosa, and prevent the formation of gallstones.

Even then, you may be losing under 800-100 g of fat daily. If you have 20-30 kg of extra weight, that's 200-300 days on a very restrictive diet. Tough!!! Those figures above must be, of course, adjusted to person's weight and levels of activity!)

Alas, nothing remotely close is recommended by either the Atkins, South Beach, Ornish, or Zone diets.

Why, then, do so many people report losing between 5 to 15 lbs (2.2- 6.8 kg), particularly in the beginning (during the induction stage)?

They report phantom weight loss, meaning mainly the loss of body water, foods in transit, and accumulated stools. Fat loss - almost none... No wonder it's so difficult.

Here is a real life example: David Blaine, who spent 44 days without food, emerged from his glass cage 55 lbs (25 kg) lighter. Assuming 20 of those pounds were phantom weight loss (he'd been stuffing himself with loads of food just before going in), the magician was losing 0.79 lb (358 g) per day. And that was definitely at the high-end of the scale-hanging in a transparent box in the center of London under the 24/7 scrutiny of gawking crowds requires a great deal more energy than a simple, straightforward fast.

I explain this phenomena (phantom vs. real fat loss) in greater details in my book entitled Fiber Menace, Chapter 3, Atkins Goes To South Beach. You can obtain the entire PDF of this chapter here:

The actual research came out from my forthcoming book Fixing Up The Atkins Diet, also describe above.

Konstantin Monastyrsky,
the author of Fiber Menace.



Victor is fundamentally right, but infuriatingly simplistic. No diet works for everyone and few program diets work over the long haul because people get tired of them and because it is devilishly difficult to change one's behavior. One can understand the math -- calories in vs. calories spent -- but it's still hard. One promising approach is that of a Birmingham, Ala., endocrinologist, David Bell, who was seriously overweight himself and realized he had to find out what would work for him or else have a stroke and die. He lost 125 pounds and has kept it off for 4 years by eating one meal a day and walking one hour a day. That's it. He doesn't count calories or eat special meals, but just by limiting his food intake to once a day he trimmed his calories to a reasonable amount. The exercise also works and, presumably, boosts his metabolism. But he points out that this is not a plan for everyone.


Some Random Guy on the Internet

Didn't we do this before already? Just just drink unflavored sugar water between meals:


I have been avoiding processed sugars for more than a month now and I gym-exercise about 4 times/week...walk for about 30 mins every day...I managed to lose 10lbs in the period...

Earlier...not an ounce, or so it seemed to me,despite all my gymming...

I am 40+...

I do not like pushing myself with these fin. disincentives..I am sensible enough...

Andy R.

Your incentive was not only $500. You were also losing weight for the right to talk about how your approach works, which could be worth a lot more in utility and in dollars (when the stickK diet catches on). It will be interesting to see the stats on new converts.

Tim Garrity

I read the Taube book and also the most recent Atkins book in October. I adopted the Atkins eating method (induction) and lost 30 pounds in about three months. I have since been slowly adding back carbs--not a lot--but enough to break up the monotony. I plan to lose about 15 more pounds in the next 6 months.

One thing that is important is actually following the diet you choose. I gave up coffee AND carbs, which was DIFFICULT! Once I did so, however, my life-long cravings for carbs--including french fries--stopped. My wife tries to follow Atkins, but cannot quit coffee or carbs. As a result, her cravinngs continue and she is miserable trying it. I have never felt better or slept better. I have also learned to cook, which I do twice a day--it's almost impossible to do any of these diets following the standard conveniences of the "modern diet."

My point? I agree that any change requires will power and education. It's not as simple as reducing calories. I went through years of eating 1,500 calories per day and cycling 100 miles/week--and gaining weight, because my diet was primarily low fat carbs. For the first time in my life I feel as if I am in control--and it feels great!



Sounds like a short story I read a long time ago (I can't remember the author) about a stop smoking program for men. You are under surveillance 23 hours a day. If the people running the program catch you smoking, they make you watch your wife get an electric shock. The shock increases each time until #10, at which point they start cutting off her fingers. Worked after one shock for the main character. Then he noticed the wife of the founder of the program was missing a finger...

Anecdotes vs. data

The author contrasts the results of scientific studies done on groups of people with one anecdote: his own personal experience. He says that "only 16%" of Weight Watchers participants lost 10 percent of their body weight after two years whereas his system seems to have helped one person (himself) keep below his target weight for one year. Unless I misread, he doesn't mention who gets to keep the 500$ every week he misses his target, other than a brief reference to an "anti-charity."

If so the strategy is clear: convince people stickK works, take their $15,000 checks, keep the cash from about 80% of the people. Sounds great.


I don't know about $500 but if one were paid as much as that Jared guy who lost all the weight eating sub sandwiches and now has a thriving career as their advertising spokesman, I bet just about anybody could keep it off. Look at Hollywood, where most people's careers depend on being thin. Almost everyone manages to do it, and the few who do not are pilloried as laughingstocks. My bet is that $100K would be sufficient reward for 99% of the population. Given the state of healthcare in this country, it would probably be a good investment.

Mark R

di (#24), that was a short story by Stephen King, called "Quitters, Inc." A very disturbing story.

I understand addiction...i have an addictive personality. I like to eat, and I don't dare get started with other behaviors that could lead to addiction. This one is bad enough.


Gaining weight is like smoking. It's best never to start.

In this day and age, people should get themselves on a diet as soon as they're over 5 pounds or the belt feels a bit tight. Waiting until they're over 20 pounds over makes it pretty much impossible to get it off and keep it off.


we did a "biggest loser" competition at work w/ a $50 buy-in which pays out $1k... the results have been amazing... across the 20 participants the avg is 13.4 lbs lost per person with a total weight loss of 268 lbs over 7 weeks.

Talk about incentive !$!$!


I think the best case for a diet to work is a shift in ones thinking. All of that extra weight we carry around is a glaring advertisement to those that don't have enough to eat that we (Americans)consume far more of the world's resources than a fair percentage of our population. We just can't consume and consume like crazy and looking at the extra weight as perhaps a public display of our overconsumption may help curb the desire to bulk up in the first place.


Interesting that the participants in the commercial group were given the attendance vouchers for free.
Did they not value the opportunity to participate because they it cost them nothing.

Also, interesting that you economists did not focus on this, but rather, I (physician) did.


How to lose weight:

1. Eat healthy.
2. Exercise.

It's really not that hard. Avoid processed foods and garbage like sugar and calorie dense dressings. Drink a gallon of water a day. Eat whole grain carbs. Exercise 3 times a week. for an hour. Yes, that's really all you have to do. It works every time.

Straight dieting tends to fail because people don't exercise and the body's metabolism slows down to go back to it's old weight. That's why you need to exercise to keep your metabolism at a higher rate. Removing sugar from your diet makes a big difference too. Assuming you haven't just done a work out, it digests quickly and becomes fat about 20 minutes after consumption.

People fail at losing weight because they are ignorant, don't have enough will power, or try to take a shortcut that doesn't work. What I've written above works better than all those fad diets.


I'm not really suprised to hear that most bettors are winning their money back. A website can't really show up at your house and demand that you step on the scales to prove you really lost the weight, can it?

ML Harris

Good Carbs, Bad Carbs by Taubes should be required reading for people looking to lose weight. It's not a diet plan. It's a reeducation plan. You will think long and hard about fries (AaronS #2), or about grains, whole or otherwise (Victor #3), and probably even exercise (again, Victor #3).

Cut your sugar. Don't eat grains. Or starchy vegetables or fruits. Eat meat. Eggs. Leafy veggies. fruits. cheese. dairy. With a plan.

- poster has lost 55+ lbs, maintained for almost a year now.

Konstantin Monastyrsky

Correction to my post above:

-- Even then, you may be losing under 80-100 g of fat daily. (not 800-100 g). Sorry...

Konstantin Monastyrsky
The author of Fiber Menace