Assumed: There is good reason to doubt that a registered dietitian can be trusted to help someone struggling with overweight.

One of the first things I like to say about nutritionists is that I owe my life and health to one: Theresa Wright of Renaissance Nutrition in East Norriton, Pa. I have experience or second-degree knowledge of many dietitians, and Theresa is highly unusual.

Most importantly to me, she understands food addiction better than any non-food-addict I’ve ever met. This has many practical effects, but foremost among them is that she rejects the common dietitian dogma of “everything in moderation” and “deprivation diets don’t work.” (More about that later.)

So, no one can say I am against dietitians. In fact, on my book’s website, I recommend five nutritionists whom I believe can be trusted to help people like me, and I’m eager to add more, when I find them.

I have three specific critiques of dietitians, beginning with the dogma issues. I agree that “deprivation diets don’t work,” but I differ wildly about what constitutes deprivation. One example: By choice, I gave up refined sugar (none listed in the first five ingredients on a product label) more than 20 years ago, and I don’t feel deprived. I grant that many would, but that’s a mindset, not a necessary condition.

If there is a valid reason to give up a substance, to me it should be part of a dietitian’s portfolio to explain that, instead of throwing in the towel before even trying. That assumes a valid reason exists, of course, which gets us to “everything in moderation.”

Sticking with the same example, I have tried to eat refined sugar in moderation, and I have always failed. Sometimes quickly, sometimes slowly, I go off a deep end with refined-sugar products in a way I never do when I don’t use any. I have strong personal evidence that this is related to biochemistry, and know thousands of people who would say the same thing. This is not hyperbole.

If someone has repeated stumbles trying to moderate refined-sugar intake, an obvious strategy would be to remove it from the diet — unless your principles start at “everything in moderation.” I know of eating-disorder treatment centers that put out sugary products at snack time “we’re going to teach you how to eat those things.” For someone like me, that’s (sugar-coated) nuts.

My other two critiques have to do with the dietitians’ trade group, the Academy for Nutrition and Dietetics, formerly the American Dietetic Association. The casual observer would think this is the authority on diet in America, and that’s what they want people to think. However, their mission statement says nothing about promoting nutrition, it is “Empowering members to be the food and nutrition leaders.” So it’s a self-interest group, not a public-interest group.

The other obvious flaw is that the AND gets about 10 percent of its funding from Big Food, the companies that make all the processed food that is making America, and the world, obese. It’s easy to see why those companies would purchase a voice within (supposed) nutrition advocacy. It’s unfathomable that any independent voice would take that money.

A last note: The AND/ADA has claimed primacy as the nation’s dietetic advisers during the entire period as the obesity rate has gone from 12 percent in 1960 to 36 percent currently. With a record like that, they should be fired.