Some 2 billion pairs of eyes will be focused on Kate Middleton as she takes the long walk down the aisle of Westminster Abbey tomorrow, and apparently she’s been slimming down in anticipation of that scrutiny. Naturally the media is all over Kate’s recent weight loss, speculating that it was achieved through France’s (and soon to be America’s) new diet craze from Dr. Dukan. The Dukan Diet is an updated and equally unhealthy twist on Atkins and it promises weight loss by restricting food choices to a few plant foods and lots of meat.

Diets that severely limit food choices are almost always effective for weight loss no matter what those foods are. Very low carb diets have the added advantage of ketone production, compounds that suppress appetite. You can’t stay in ketosis forever, though, so like most fad diets, this one is more likely to be a quick fix than a long-term solution.

The number of popular diet plans in bookstores and on the internet is a testament to the fact that, while there are plenty of ways to lose weight, long-term solutions for weight management are hard to come by. After my last blog post on vegan weight management, I heard from quite a number of readers about that. Some took issue with my approach, too. They suggested that there should be less emphasis on “weight loss,” and more on healthy lifestyle. This is part of the Health at Every Size (HAES) perspective.

The HAES paradigm addresses our national obsession with dieting and points to the fact that health outcomes can be improved in overweight people without weight loss. Some of the concerns about a weight-loss-only focus have to do with the potential damaging effects of “weight cycling,” (that is, repeatedly losing and regaining weight), as well as the damaging psychological effects associated with constant pressure to lose weight. Weight loss is also sometimes viewed as a moral imperative, which reinforces bigotry against overweight people. And of course, an obsession with weight leads people to make bad choices like the Dukan Diet.

For those who can improve their health through weight loss and wish to do so, I have no problem with providing reasonable guidelines based on vegan eating patterns. But for those who have been weight cycling for years and have not been able to maintain their desired weight, I agree that a shift in perspective toward healthy habits—with or without weight loss—can prevent damaging behaviors and outcomes. Because the truth is that we don’t really know why long term weight management is harder for some than others. It could be an inherited “thrifty gene,” that favors fat deposits, or differences in brain circuitry regarding feelings of “reward,” from eating or any of a number of other explanations that are topics of research right now.

There’s a vegan issue here, too, which I mentioned briefly in my last article and want to expand on. I’ve had quite a number of people tell me that they feel alienated from the vegan community for a number of reasons; one of those reasons is that they don’t feel welcome or like they “fit” in the vegan community because they are not models of vegan health perfection.

But this is not a problem of fat vegans. The problem lies with those who promote veganism as a weight loss diet. Although it’s been great to see so much focus on veganism in the media lately—specifically on Oprah and Martha Stewart—I’ve felt discomfort about promises that going vegan will automatically lead to weight loss.

Going vegan is unlikely to cause weight loss for most people unless they also restrict their food intake in other ways. And even embracing some of those other restrictions—like avoiding all fats—isn’t a guaranteed weight loss plan. When people don’t achieve their desired weight on a vegan diet, they are likely to decide that veganism “doesn’t really work,” or that they have somehow “failed” at being vegan. They might move on to another of the hundreds of diets that promise weight control, or—if they embrace the ethical reasons for being vegan—feel uncomfortable talking about their veganism to others if they believe that they aren’t portraying veganism in a good light.

False promises about health and weight loss also shift the focus away from the ethic of justice that is the basis of veganism and animal rights. Being vegan is about what’s in our hearts, not what’s on our hips. It’s a refusal to use animals for our own pleasure and convenience which makes it a choice that is available to everyone. If we want a vegan world, then we need to build a vegan community where everyone feels comfortable and accepted. That will never happen as long as we define veganism as a weight loss diet.