Friday, April 18, 2008

Losing weight and keeping it off

As I mentioned in my last post, there is significant debate over the rate of success in losing weight and keeping it off without the use of surgery or drugs. However, it is definitely possible for some people, and there has been great interest in characterizing the behaviors of those people.

Many, but not all, of the studies I will mention in this post use subjects in the National Weight Control Registry (which I will refer to as the NWCR). They have a pretty detailed website, so if this subject is of interest, you might want to check it out. While this is a tremendously valuable resource in the study of successful weight loss maintenance, in general, I would say that the studies that come out of this cohort are slightly less reliable, because the analysis is retroactive in nature, meaning that the people's habits are being studied after they have lost weight and kept it off. Other studies, in contrast, have looked at people's habits immediately after losing weight and then looked to see what lifestyle factors ended up being associated with maintaining that loss. The former approach is more susceptible to something called recall bias, meaning that the fact that the people being studied have already successfully maintained their weight loss might affect their memories and perceptions of their own habits as compared to people who did not maintain weight loss. With that caveat (and you can tell which studies are NWCR-related by the authors...Rena Wing and James Hill are the founders of the registry), here is a summary of some of the major findings.

Diet--The following dietary habits have been found to be associated with successful maintenance of weight loss:
-Eating five or more servings of fruits and vegetables per day (1, 2)
-Not eating at fast food restaurants (as compared to those who eat fast food at least twice a week) (1)
-Using low-calorie pre-packaged meals (2-4)
-Practicing portion control (2, 11)
-Moderating intake of fat (2, 11)
-Eating breakfast (11)

Exercise: Multiple studies have found that exercise improves one's chances of maintaining weight loss (1,2, 5-8). There is some debate, however, over how much exercise is necessary. Several studies have suggested that an hour of exercise each day is needed to improve chances of weight loss maintenance (1, 2) but at least one other study found that any amount of exercise was beneficial (5)

Weight loss as a percentage of starting weight:
Multiple studies (5, 9, 10) have shown that basically, the more weight you lose, the harder it is to maintain. For this reason, many public health officials are now recommending that obese people strive to lose 10-15% of body weight and keep it off rather than trying to achieve a "normal" BMI and then rebound.

"Screen time": Television and computer use (outside of work) has been shown to be positively correlated with weight regain (5)

Consistent Monitoring of Weight: One of the characteristics identified in subjects in the NWCR was frequent weighing (11). 44% of these people said they weighed themselves daily and 31% weighed themselves weekly (11). A more detailed study also showed that subjects in the NWCR who started weighing themselves less frequently gained more weight than those who maintained their strict weighing schedule (14). However, it's not clear whether weighing itself somehow affected these people's motivation to maintain their weight or whether people who knew they'd "slipped" a bit had more trepidation about stepping on the scale regularly.

Online Support:
A recent study published in JAMA (12) looked at people who had lost weight through a 6-month program of monitored diet and exercise and then looked at the efficacy of three different types of counseling in helping them to maintain their weight loss over 30 months. Following the initial weight loss period, the "self directed" group were given some literature with recommendations for diet and exercise and met with a counselor after 12 months. An "interactive technology-based intervention" group was given unlimited access to a web site which assisted them in monitoring their weights, monitoring their caloric intake and physical activity and charting their progress, as well as giving them access to a message board where they could interact with other members of that group. The third group received monthly personal contact with a counselor either over the phone or in person. While all three groups regained some weight, they found that the technology-based intervention group regained less than the self-directed group, and the personal contact group regained the least.

While personal monitoring of weight maintenance may not be widely feasible, this does suggest that support provided through the internet may assist in weight loss maintenance. However, at least one other study (13) had different findings that a (different) website they set up to support maintenance of weight loss after a 4-month weight loss program did not make any difference in maintenance of weight loss. The authors attributed the lack of effect to the fact that many of the participants in the study were not comfortable using the internet.

Other: Interestingly, 2 found that unsuccessful maintainers were more likely to follow popular diet books than those who were successful at maintaining weight loss.

Anyway, I doubt any of these things are shockers, but it may be a helpful collection of information for some people!

1. Kruger J, Blanck HM, Gillespie C. Dietary Practices, Dining Out Behavior, and Physical Activity Correlates of Weight Loss Maintenance. Preventing Chronic Disease, 5:A11, 2008.

2. Befort CA, Stewart EE, Smith BK, Gibson CA, Sullvan DK, Donnelly JE. Weight maintenance, behaviors and barriers among previous participants of a university-based weight control program. International Journal of Obesity, 32: 519-526, 2008.

3. Heymsfield SB, van Mierlo CA, van der Knaap HC, Heo M, Frier HI. Weight management using a meal replacement strategy: meta and pooling analysis from six studies. International Journal of Obesity and Related Metabolic Disorders 27: 537-549, 2003.

4. Ditschuneit HH, Flechtner-Mors, M. Value of structured meals for weight management: rsk factors and long-term weight maintenance. Obesity Research 9: 284S-289S, 2001.

5. Weiss EC, Galuska DA, Khan LK, Gillespie C, Serdula M. Weight Regain in Adults Who Experienced Substantial Weight Loss, 1999-2002. American Journal of Preventative Medicine, 33: 34-40, 2007.

6. Anderson JW, Konz EC, Frederich RC, Wood CL. Long-term weight-loss maintenance: a meta-analysis of U.S. studies. American Journal of Clinical Nutrition 74: 579-584, 2001.

7. Jeffery RW, Epstein LH, Wilson GT,
Drewnowski A, Stunkard AJ, Wing RR, Hill DR. Long-term maintenance of weight loss: Current status. Health Psychology 19 5-16, 2000.

8. Grodstein F, Levine R, Troy L, Spencer GA, Colditz GA, Stampfer MJ. Three-year follow-up of participants in a commercial weight loss program: can you keep it off? Archives of internal medicine 156: 1302-1306, 1996.

9. McGuire MT, Wing RR, Klem ML, Lang W, Hill JO. What predicts weight gain in a group of successful weight losers? Journal of Consulting Clinical Psychology, 67: 177-185, 1999.

10. Vogels N, Westerterp-Plantenga MS. Successful long-term weight maintenance: a 2-year follow-up. Obesity 15: 1258-1266, 2007.

11. Klem ML, Wing RR, McGuire MT, Seagle HM, Hill JO. A descriptive study of individuals successful at long-term maintenance of substantial weight loss. American Journal of Clinical Nutrition, 66: 239-246, 1997.

12. Svetkey LA, Stevens VJ, Brantley PJ, Appel LJ, Hollis JF, Loria CM, Vollmer WM, Gullion CM, Funk K, Smith P, Samuel-Hodge C, Myers V, Lien LF, Laferriere D, Kennedy B, Jerome GJ, Heinith F, Harsha DW, Evans P, Erlinger TP, Dalcin AT, Coughlin J, Charleston J, Champagne CM, Bauck A, Ard JD, Aicher K for the Weight Loss Maintenance Collaborative Research Group. Comparison of Strategies for Sustaining Weight Loss. Journal of the American Medical Association, 299: 1139-1148, 2008.

13. Cussler EC, Teixeira PJ, Going SB, Houtkooper LB, Metcalfe LL, Blew RM, Ricketts JR, Lohman J, Stanford VA, Lohman TG. Maintenance of Weight Loss in Overweight Middle-aged Women Through the Internet. Obesity, advance online publication, 2008.

14. Butryn ML, Phelan S, Hill JO, Wing RR. Consistent Self-monitoring of Weight: A Key Component of Successful Weight Loss Maintenance. Obesity 15: 3091-3096, 2007.


Sony said...

About five years ago, when I was deciding whether or not to get a lap band (I did and now I regret it) I found an NIH paper that talked also about the physical attributes of people who were successful - typically they were younger, they gained weight as adults, and they had only been at the higher weight for a short time. I'm too busy to go look that up right now, but I'd be interested to know if there is other support for that.

I remember having that piece click into place for me when I was reading Rethinking Thin and Kolata wrote about the Sims prison experiment (the chapter is basically this article:
and it seemed to me that maybe some of the "successful weight loss stories" are really stories of people for whom the gain was the aberration, not the loss.

For example, a friend of mine "lost" fifty pounds that she gained while pregnant and kept on through a couple of years in an emotionally abusive marriage. When she got a divorce she started losing weight. She's very thin now, She was very thin before she met her ex, and really doesn't do anything to maintain her weight now.

So is she a success? She lost about 30% of her highest weight, but it seems like her weight loss is an apple to my orange in terms of the body type she's got, the reasons she gained it, and the way she's maintaining it. I don't know how to define that.

Dr. LaWade said...

Sony, it would certainly make sense that people who had been heavier for a shorter amount of time would have an easier time maintaining weight loss. But given the nature of these studies, I would be very surprised to find that loss of "aberrant" weight accounted for a large percentage of those successes. Weight loss programs based at academic centers tend to try to recruit people who have been obese for some time and who have not had success trying to lose weight in the past.

Jane Doe #4 said...

The thing that has always made me skeptical of the NWCR-based studies is that I've never seen them compare the characteristics of "successful losers/maintainers" to other groups of people (people who have never lost 30 pounds, people who lost that amount but regained it, etc.). I bet the majority of people in the NWCR have 10 fingers and 10 toes, and I bet the majority of them sleep at night and are awake during the day, but I have no reason to think the former characteristic or the latter behavior is in any way related to their weight loss and maintenance. If the type of people tracked by the NWCR were shown to be *more likely* to have 10 fingers and toes, or to sleep at night and wake during the day, than other types of people, *that* would be worth talking about. Admittedly, I didn't go look up the particular papers you cited, but I've never seen such a comparison in any of the NWCR stuff I have read.

Dr. LaWade said...

Jane Doe, all the papers mentioned in this post compared successful losers to controls and found that the behaviors mentioned were more prevalent in the successful losers.

Mary said...

Permanent weight loss has been achieved if one doesn't need to keep constant watch over what one eats in order to maintain the weight goal.

The most important factor in permanent weight loss is the formation of habit; specifically, the habit of eating the amount of food necessary to reach and maintain the desired weight. It isn't what we eat that makes us gain weight; it's how much. Permanent weight loss can occur regardless of what we eat, and whether or not we exercise.

Habit formation cannot occur when the dieter radically reduces the caloric intake day after day. One cannot form the habit of permanent weight loss, eating in a manner that is impossible to sustain indefinitely. Sooner or later, the body will rebel and force the dieter off the wagon.

Habituation to desired weight does occur when the dieter alters the caloric intake on an every-other-day basis, and continues dieting to the weight goal. Habituation -- using a low amount and a higher amount, consistently, every other day -- takes 21 days. What's more, both calorie amounts are usually higher than one would expect. No one has to eliminate 500 calories from their daily intake in order to lose one pound. After all, some overweight people normally eat less than that daily.

With consistent use of the correct calorie allowances on both days, weight loss is automatic and the plateau length is predictable, regardless of how much the dieter has to lose. To stop dieting, one simply drops the low-calorie day once the desired weight is achieved. Habit, formed in the first 21 days, ensures that the weight loss is permanent.

Not only is the every-other-day method safe for those in good health; it is also impossible to use it for too long.

The foregoing method is difficult to credit only if one has never tried it -- for 21 days.

Anonymous said...

I've never been obese, but was slightly overweight a few years ago after returning to Australia after living in the UK for two years. Normally an active person, I lived in a cramped apartment in London and the lifestyle there was less open to activity, and good food (vegetables, etc.) were expensive so I tended to buy bad/fast foods. Easy to see why I put on a bit of weight.
As soon as I got home, I realised I felt bad about my weight and, instead of reading endless studies, thinking about BMI, going on fad diets, etc., I did what I believe is the ONLY OPTION if you want to lose weight. I may be oversimplifying and I think this applies more to people like me who were a bit overweight and are used to being trim, but seriously - it's simple isn't it? EAT LESS. EAT WELL. EAT A BALANCED AND REASONABLE DIET. EXERCISE MORE. I lost the weight, and was back to normal. Recently, I decided I wanted to lose even more weight and really tone myself up. So I ate even better, cut out even more bad foods, and exercised even more - and it worked.

I sometimes think the endless chatter about what is best, what foods to eat, what amount of protein you should eat as opposed to carbohydrates, etc., etc. just freaks people out and makes them think that losing weight is a tricky thing that scientists/doctors need to help us do. Sometimes the simplest explanation/course of action is often the most effective. Isn't it good to know that it is pretty obvious what you need to do to lose weight?

I understand that a lot of the time overweightness (is that a word?!) could be a sign of depression or anxiety, or just feeling lost in life, so this shouldn't be discounted. I don't know, that's just my experience.