Yogurt and Nuts Correlate With Weight Loss: Why?

A new longitudinal study finds:

Despite conventional advice to eat less fat, weight loss was greatest among people who ate more yogurt and nuts, including peanut butter, over each four-year period. . . .

That yogurt, among all foods, was most strongly linked to weight loss was the study’s most surprising dietary finding, the researchers said. Participants who ate more yogurt [than the average for all participants?] lost an average of 0.82 pound every four years.

Why might this be?

Yogurt and peanut butter are both unusual foods. Yogurt is strange because unflavored yogurt has little or no smell. It tastes good for other reasons: strong sourness, creaminess, and coolness. People are also pushed to eat it not only by how pleasant it is to eat but by the thought that it is good for them. Most foods, in the form that we eat them, have a smell. I explain the yogurt results by saying that yogurt consumption replaced consumption of foods with stronger smells.

Peanut butter is unusual because when I was visiting publishers to sell The Shangri-La Diet, I met a woman who told me she had lost weight simply by eating peanut butter — that is, by adding peanut butter to the rest of her diet, making no other changes. I think she ate about 3 tablespoons per day. This predisposed her to think there might be something to my ideas. No one has ever told me such a story about another food. If peanut butter has a smell, it’s really weak. It’s pleasant to eat because of fat content and texture. When I was a boy, my mom made me peanut butter sandwiches (no jam) for school lunch. I never came to like them. This implies I never learned a smell-calorie association. The bread must have supplied a strong fast calorie signal so this implies that the peanut butter generated little or no smell signal.

Thanks to Eri Gentry.

10 Responses to “Yogurt and Nuts Correlate With Weight Loss: Why?”

  1. Glen Raphael Says:

    If you google “peanut butter diet” you find a lot of recipes that involve adding peanut butter to familiar foods. Mix peanut butter into your oatmeal or your maple syrup or what-have-you. That seems like a form of “crazy spicing” to make your familiar foods taste a little strange. If the peanut taste is dominant it could also make your overall diet seem more bland.

    I may have to try it and report back.

  2. David Says:

    I’ve also noticed an SDL-effect with scrambled eggs and toast or tortilla. No strong smell -> weight loss.

  3. Elisa Says:

    Eh? Peanut butter is one of the most recognizable smells. It’s a strong smell. I think it’s the fat. Eating a spoonful of peanut butter is similar to drinking a tablespoon of oil (but much tastier).

  4. Weston Says:

    I’ve got to agree with Elisa. I would not categorize peanut butter’s smell as “really weak”

  5. Kirk Says:

    But without the data, it’s all speculation. I can just as easily explain the yogurt results as a replacement of ‘bad’ gut bacteria with ‘good’ bacteria, which leads to signals by the ‘good’ bacteria to the brain to ingest more nutritional food and less junk food. Or another explanation: people who eat yogurt generally eat more nutritious food in general than those who don’t. Also, most yogurt on the store shelves is flavored and sweetened. That’s why I would want to see the data, in detail. The study was supported by grants from the NIH; as a taxpayer, I want that data made available for analysis by others (presuming, of course, that the identity of the participants can be obscured.)

  6. Justus Says:

    Isn’t the real news that 0.82 pounds over four years is pathetic? Would you change your diet if you were told it would help you lose a quarter of a pound a year?

  7. Seth Roberts Says:

    Kirk, in my experience speculation based on data is where good ideas begin. Where experiments begin. For example, this result might be followed up by an experiment where people deliberately eat yogurt. That would help establish cause and effect. If yogurt really did cause weight loss I would predict that flavored yogurt would cause less weight loss than unflavored yogurt. If that were true it would support my explanation (lack of smell) over yours (replacement of bad gut bacteria) because my explanation would have made a correct prediction. If both flavored and unflavored yogurt produced the same weight loss that would support your explanation over mine.

  8. David Says:

    Justus: If I were gaining weight and someone said eating some yogurt and nuts (not such a bad thing) would make me stop gaining weight and start losing modest amounts, I’d be interesting. So we’d have to know how the non-yogurt and nut eaters did. Anyway, you can do much better than .82/4 years with SLD techniques.

  9. Kirk Says:

    That would be an interesting experiment; a group eats plain yogurt, another group eats flavored yogurt. If they ate the yogurt only during an SLD-like eating window, then I agree the plain yogurt folks would probably lose more weight. I don’t think SLD would apply if they ate the plain yogurt with other foods.

    The thing is that this longitudinal theory suggests three theories to me, and I sympathize with all three theories.

    The first theory is SLD. I agree that SLD techniques work. Used them myself. As for the impact of SLD on this study, I suspect little impact, unless the data shows that people took extra effort to eat certain foods during an SLD-like eating window.

    The second theory could be labeled the Paleo eating theory. If I had to make bets on this particular longitudinal study before seeing the detail, this is the theory I would choose as to what influenced the weight loss. I suspect that the people who lost weight shopped the edges of the grocery story . . . they ate fresh fruit, fresh vegetables, meat, fish, eggs, cooked their own food, avoided industrial seed oils and processed foods, ate fewer neolithic grains, and so on; the way of eating as articulated by Robb, Mark, Chris, Kurt, and Paul and Shou-Ching.

    The final theory, and it’s a long shot, is the influence of good bacteria. I’d be tempted to place a ‘long bet’ on bacteria therapy as an eventual cure for obesity.

    As for yogurt, the shelves are crowded with flavored yogurt, and my guess is that most people who buy plain yogurt take it home to eat it with their own favorite flavoring . . . cinnamon sugar, honey, maple syrup, or their favorite granola.

    To me, peanut butter has a strong smell. That would be an interesting experiment for you and your friends . . . a blind smell test, and include peanut butter amongst the candidate foods. Perhaps peanut butter is a bland smell to you. I just ran a (visible) test and found that I could identify the smell of peanut butter when my nose was positioned 4 inches above a open jar.

  10. Kirk Says:

    from http://www.swissbusinesshub.com/photos/news/YogurtMarket_US.pdf

    Sales and Market Share by Flavor (2001)

    Flavor, Value ($ Millions)
    Plain, 123.4
    Vanilla, 150.8
    Flavored, 1995.9