Seth's Blog

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.

This shows Justin Wehr‘s weight over two years. He is 26 years old and 6 feet 2 inches tall — at 140 pounds, very thin. The record begins with a switch to a vegan diet. Over three months he lost seven pounds but gradually regained the lost weight, even though his diet didn’t change. In the middle he suddenly gained five pounds on a trip to Alaska and Seattle and then gradually lost it.

He describes his diet like this:

My diet was pretty average Midwestern meat and potatoes sort of thing prior to going vegan-ish, and I emphasize the ish. I’ve been vegan-ish since I started tracking weight, meaning that I don’t buy meat or dairy products at the store, but I’ll happily eat whatever sounds good off of a restaurant menu or whatever is being served when I’m eating at someone else’s place. I intentionally keep my diet very boring. I eat an absurd amount of peanuts and raisins, I estimate in the range of 600 – 900 calories per day. Besides peanuts and raisins, most of my calories come from lentils, frozen vegetables, and bread + olive oil. I drink almost exclusively water, with a few swigs of OJ most days, and have a glass of wine or a bottle of beer on occasion.

The features of this data that interest me are (a) weight loss when he changed what he ate (first three months) and (b) gradual regain of the lost weight (after that). Few theories of weight control can explain the regain. However, the theory behind the Shangri-La Diet can. It says that he initially lost weight because he shifted to foods with relatively weak flavor-calorie associations — weak because the foods were relatively new. As he ate them again and again, the flavor-calorie associations got stronger and this raised his set point.

I’ve done several experiments where I add a bunch of randomly-chosen spices to butter, spread the butter on saltines, eat the saltines, and then follow (or not follow) them with a piece of Wonder Bread eaten with my nose clipped shut.

In the previous experiment in this series, I made two spice mixes, A and B. After eating saltines spread with A, I ate a piece of bread. After eating saltines spread with B, I ate nothing. I did one trial per day, going back and forth between a trial with A and a trial with B. For example, Monday (A Trial), Tuesday (B Trial), Wednesday (A Trial), etc. Here are the results:

In an experiment just finished, I improved this design a bit: 1. I had trials with both A and B on the same day. (I made two new random spice mixes for this experiment.) 2. The first saltines of the day I rated “blind” — that is, without knowing what mix it was. Here are the new results superimposed on the previous results.

So far so good. The new results agree with the earlier results.

In this interesting video about losing weight, Paul McKenna, a British hypnotist, recreates a study in which people ate food blindfolded. In the study, they ate one-quarter less when blindfolded than when not blindfolded. This doesn’t impress me; nothing is stopping the blindfolded subjects from eating more at later meals. But it makes me wonder how not seeing your food affects flavor-calorie learning. It might make it stronger (you’re less distracted) or it might make weaker (the sight of food acts like glue to strengthen flavor-calorie associations — there is actually evidence for something like this).

While wearing noseclips while eating with others is too weird, wearing dark sunglasses might not be. And what about listening to music (for distraction) while you eat? My calorie learning experiments are continuing; eventually I should be able to test these possibilities.

Thanks to Gary Skaleski.

I made random flavors by mixing 4 randomly-chosen spice mixtures into butter. I spread the butter on 2 pieces of Wonder Bread. I used each mixture more than once — twice in a row (1st mixture), three times in a row (2nd mixture), four times in a row (3rd mixture). Each trial consisted of a flavor-calorie pairing — flavor from the spices, calories from the bread. Each trial also provided a rating, which measured the learning.

Here are the ratings of how good the bread tasted.

This was good. 1. The ratings started near 50 (neutral) each time. I’d like to have a large supply of flavors so that I can start fresh each time. These results suggest that randomly mixing 4 spice mixes provides this. The 4 spice mixes were randomly chosen from 10 spice mixes — so there are a lot of possible combinations. 2. The learning per trial was substantial.

More in the category Calorie Learning.