The Psychology of Dieting Part 6: The Curse of Variety

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Plate with a Variety of Food

In August, I joined a “Biggest Loser” competition at work, in which people in the office compete to lose the largest percentage of their body weight. A week before the competition began, I started tracking my dietary consumption in order to measure what actually causes me to gain and lose weight. As I have consistently been near the top of the pack during the competition, many people have approached me to ask how I do it…

My first response, of course, is that I don’t know. “I’m still collecting the data,” I say, “but I should be able to tell you with some degree of statistical certainty within a few weeks.” This answer, however, isn’t usually what people are looking for, and I tend to get blank stares when I offer it. Not many people quantify the variables that could influence their weight loss when they start dieting. They simply try some kind of diet and, if it works, assume that it’s because of that diet that they lose weight.

So, instead of telling them that the jury’s still out, I offer a different answer that I believe to be true. It’s an answer that I think everyone knows but few people want to admit–because it’s hard to do. But I really do think it’s the secret to weight loss. Are you ready for it–this groundbreaking revelation of dietary genius? Okay, here it is…


Yep, it’s that simple. You can’t gain (or even maintain) weight if you don’t eat. If you consume less food than your body can store, it seems obvious that you will lose weight. And I think that has proved true in my case–I’ve averaged 1,500 calories since I started dieting, but I have not given up any particular food and I haven’t exercised at all.

When I tell people that I think, if they want to lose weight, they need to eat less food–the response intrigues me. They seem to disregard the advice and go into monologues about the diets or work-out routines they think work. People are looking for me to say, “I run 5 miles a day” or “I’m on the Atkins/Mediterranean/Paleo/South Beach Diet.” My answer of “eat less” just seems to simple, and I don’t think they want to hear it.

But it is that easy. And yet…it’s also that hard.

The problem, I think, is mostly psychological. People don’t know how to eat less, so they try instead to find different ways of “eating right.” Restraint is difficult. It takes discipline to not go back for seconds when you’re still hungry. When resources are abundant like they typically are in our country, people tend to eat until they’re full and–if it tastes good enough–even more. How do you lose weight? You eat less. But how do you eat less? That’s a different question entirely.

Over the past few months, I’ve been sharing some of the most interesting research from Dr. Brain Wansink that I think provides great insight into how to eat less in order to lose more. This post will be the sixth and final topic that I cover in the series. In case you missed them, here are links to the first five:

Variety is the Spice of Dieting

One of the most interesting ways to fool yourself into eating less without feeling like you’re eating less is to put a smaller variety of foods on your plate. The greater the variety of food, the more food you are likely to eat overall because you tend to take a greater helping of each kind of food. But a 2004 study published in the Journal of Consumer Research reveals that it’s the more the perception of variety than variety itself that influences our food intake…

In one set of studies, the researchers tested the consumption activities of both a group of children and a group of adults. For each group, the researchers offered the subjects a tray of jelly beans–consisting of either 6 or 24 different colors. Part of the subjects received trays in which the colors were all mixed together, and the other part of the subjects received trays in which the colors were clearly separated.

Impact of Assortment Structure

At the end of the study, the researchers tallied how many jelly beans the members of each group had taken. As for actual variety, there was virtually no effect on how many jelly beans subjects took from the trays. However, when the colors were organized and the variety of colors could be clearly seen, subjects took 2-3 times as many jelly beans from the trays with 24 colors as they did from the trays with only 6 colors. When people are able to clearly see a greater variety on the plate, they choose to eat more.

In another study, the researchers tested this idea yet again–throwing in the variable of plate size. In this study, participants were offered trays of M&Ms containing 6 different colors. Part of the subjects were again offered disorganized mixed of colors and the other part was offered organized and distinct groups of colors. This time, though, the researchers served a standard size tray to part of subjects and a larger tray (with double the proportions of each color) to the other part of the subjects.

Plate Size and Variety

Again, when the colors were disorganized so that people could not clearly see the variety, the size of the tray had no effect on how many M&Ms participants took from the trays. However, when the M&Ms were clearly set apart into distinctive groups of color, people who had taken from the larger tray took 3-4 times as many M&Ms than those who had taken from the smaller tray. So, when perceived variety increased, the effect of the plate size on consumption also increased.

So, What Does This All Mean?

Why do people tend to eat more when they are served a greater variety of food. My guess is that they feel like they have to take “enough” of each kind of food. When they can clearly see the different kinds of food, people don’t look at the quantity of the entire meal so much as they look at the quantities of each individual food. For example, you wouldn’t see a plate filled with steak, potatoes, fried vegetables, fried rice, cubed cheese, and cherry tomatoes; instead, you see how small your steak is, the tiny dollop of mashed potatoes, how few cheese cubes you have, and so on.

So, how can you implement this research into your diet to help you eat less and, consequently, lose weight? Here are a few tips:

  • Mix your food together. When possible, make your meal into a salad. When you mix everything together, you see the overall quantity you are eating rather than the quantities of each item. This way, you can get all the nutrition you need without taking too much of each food.
  • Eat fewer kinds of food. I suspect that we need a lot less food than we’ve been trained to believe. If you just glance at the “percentage daily values” from any given meal, you will see how quickly the necessary nutrition adds up in our consumption. You don’t need meat in every meal, for example. Space out your necessary nutritional intake across meals–thereby enabling yourself to eat few kinds of food for each occasion.
  • Eat from a smaller plate. You can’t really go wrong with this one. If you eat from a smaller plate, the effect of variety is severely diminished because (as discussed in Part 1 of this series) we tend to eat to get full in proportion to the size of the plate on which we’re served. We want to eat until all the food on the plate is gone–regardless of the plate’s size. Therefore, we will eat less from a smaller plate.

featured image courtesy of Bob Peters, licensed via Creative Commons.

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