Episode Details

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In the last newsletter, I gave a general overview of Weight Watchers (aka WW) and all the tricks they use to sell a program that doesn’t work. Today I’m going to dig into the research. I started at Weight Watcher’s own “Science Center.” They pointed to two studies to back up their claim that “WW is one of the few programs that fulfills all of the criteria that expert panels deem necessary in order for behavioral lifestyle weight-loss interventions to be effective”

First of all, that’s…a lot of words. I’m going to move beyond some questions like - what criteria, and panels of what kind of experts? Instead, I’ll point out that they seem to be taking great care with this phrasing to avoid saying that their program is actually effective. I think that a review of the research will help clarify that choice.

At any rate, the first study they cite is Extended and standard duration weight-loss programme referrals for adults in primary care (WRAP): a randomised controlled trial

This 2017 study compared three groups of people who were all 18 or older with a BMI of 28 or higher. They looked at three interventions:

1.       Brief advice and self-help materials

2.       12 weeks of Weight Watchers

3.       52 weeks of Weight Watchers

They checked in with participants at one and two years. (Of course, most people gain their weight back within five years but we’ll get to that in a moment.)

They started with 1,269 participants, 823 completed the one-year survey, and 856 completed the two-year survey.

At year one

Brief intervention: average loss of 7.19lbs (3.26kg)

12-weeks of Weight Watchers: average loss of 10.47lbs (4.75kg)

52-weeks of Weight Watchers: average loss of 14.9lbs (6.76kg)

So, on average, people in Weight Watchers for 12 weeks lost 3.3 more pounds in a year than the people who didn’t participate in Weight Watchers at all, and the people in the year-long program lost 7.7 pounds more in a year than those who didn’t participate in Weight Watchers and 4.4 pounds more in a year than people who were on the program for 40 fewer weeks than they were.

Ok, before we go further, I feel compelled to remind you that I didn’t cherry-pick this study to make fun of it, it’s literally the first study that WW points to as proof of their efficacy.

Year two

The study says “Differences between groups were still significant at 2 years” which seemed oddly nonspecific. Luckily, they included a graph to elucidate:

The graph makes it clear that, in actuality, differences among the groups had collapsed by year two, and everyone was on track to regain all of their weight (a reminder that if a variable is going straight up, the most basic research methods require that we not assume that it will level off the moment we stop tracking it.) And, of course, while everyone is gaining their weight back, Weight Watchers doesn’t refund money spent on program fees, cookbooks, WW-branded food and merchandise etc.

How did the study authors “interpret” these results?The “interpretation” section says

“For adults with overw*ight* or ob*sity, referral to this open-group behavioural weight-loss programme for at least 12 weeks is more effective than brief advice and self-help materials.