A couple people have e-mailed me (thank you) about Bob Greene saying on Larry King that it’s healthier to yo-yo diet than stay fat. Specifically:
King: Is fluctuating weight like Kirstie Alley bad, Bob?
Greene: Well, there’s two sides to that story. First off, if you remain heavy, that’s when the most damage is done to your heart and the excessive health ramifications from keeping overweight. So as long as you’re watching, even if it’s yo-yo dieting, that’s healthier than the person that remains heavy.
Except for how that’s probably the opposite of true. I’m too distracted for a full rant right now, but Shinobi’s on it, and I’ll tell you what I just told her in comments. I just re-read the big 2007 UCLA metaanalysis of weight loss studies (PDF). They recommend further study on weight cycling, because the current data is (or was) inconclusive — but it doesn’t look good at all. Money quote:
“In sum, the potential benefits of dieting on long-term weight outcomes are minimal, the potential benefits of dieting on long-term health outcomes are not clearly or consistently demonstrated, and the potential harms of weight cycling, although not definitively demonstrated, are a clear source of concern. The benefits of dieting are simply too small and the potential harms of dieting are too large for it to be recommended as a safe and effective treatment for obesity.”
And here’s what comes right before that:
It is also possible that weight regain leads to health problems of its own. An analysis of the benefits and harms of dieting must consider the potential harms of weight cycling. Weight cycling, the repeated loss and regain of weight, is commonly observed in dieters (Brownell & Rodin, 1994; National Task Force on the Prevention and Treatment of Obesity, 1994). There is evidence from largescale observational studies that weight cycling is linked to increased all-cause mortality (Blair, Shaten, Brownell, Collins, & Lissner, 1993; Lee & Paffenbarger, 1992) and to increased mortality from cardiovascular disease (Hamm, Shekelle, & Stamler, 1989). In addition, weight cycling is associated with increased risk for myocardial infarction, stroke, and diabetes (French et al., 1997), increased highdensity lipoprotein cholesterol (Olson et al., 2000), increased systolic and diastolic blood pressure (Kajioka, Tsuzuku, Shimokata, & Sato, 2002), and even suppressed immune function (Shade et al., 2004).
It has often been suggested that the harmful effects of weight cycling result from unintentional weight loss (i.e., from smoking or illness) rather than from intentional dieting (French & Jeffery, 1994; National Task Force on the Prevention and Treatment of Obesity, 1994). However, at least two large-scale studies that controlled for unintentional weight loss still found that intentional weight loss is linked to mortality risk (Andres, Muller, & Sorkin, 1993; Pamuk, Williamson, Serdula, Madans, & Byers, 1993), and the balance of evidence does seem to implicate intentional weight loss in adverse health outcomes.
Shut up, Bob Greene. Shut up a lot.