June 5, 2001 -- Variety may be the spice of life, but when it comes to food, the myriad of choices served up at a buffet spread or on sale at your local mega-market may put you on the road to obesity. Researchers have found that dietary variety increases food consumption -- which eventually causes weight gain -- in both humans and animals.
"In humans, when there is more variety in a meal, and in animals when there is more variety in a diet, both humans and animals tend to eat more. ... And by variety, I mean sensory variety: The foods have different tastes and textures and colors," author Hollie Raynor, MS, RD, tells WebMD.
A review of 58 studies that looked at variety of foods and obesity revealed that "... animals with more varied diets tend to be bigger -- they tend to weigh more and have more percentage body fat," according to Raynor, a registered dietician and a doctoral student in clinical psychology at SUNY at Buffalo.
This happens because humans (and animals) are more likely to experience what researchers call 'sensory-specific satiety' when given one food. That is, they are more likely to get tired of the taste of the food and stop eating when they are actually full, as opposed to wanting to taste the different foods available.
"'Sensory-specific satiety' argues that if you are eating foods that are similar in sensory characteristics, then the overall ratings of those foods during your meal should decrease more rapidly than during a meal with very different foods," says Raynor. "Therefore, you will just get tired of a food, it won't be so pleasant, and you'll stop eating more rapidly than if put in a situation where there are lots of different foods."
"Clearly, if you are just eating one food -- regardless of whether it is Twinkies or chocolate pudding or broccoli -- it becomes tedious and boring, and all the non-nutritive value in eating is lost: the enjoyment aspect of it, the sensory aspect of it, and probably even the social aspect of it," says Edward Abramson, PhD, professor of psychology at California State University, in Chico, and author of Emotional Eating: What You Need to Know Before Starting Another Diet.
The importance of the non-nutritive values of eating should not be underestimated, says Abramson, who was not involved in the study.
"Eating serves a variety of functions. Obviously the nutritive is basic, but above and beyond that, when you think of all the different functions that food serves, it is easy to see why people gain weight," he says. "We socialize around food, we reward ourselves and each other -- especially children -- with food, we use food sometimes to cope with stressors or unpleasant emotional states, we use food to celebrate, and mealtimes are markers in our days. So we have certain expectations."
Eating is not only about hunger, says Abramson.
"Attractive food is very hard to resist; it is not physical hunger, but physical hunger makes it worse, because then it is harder to regulate your food intake," he says. "Food also has rewarding properties to it, aside from the fact the taste is appealing: It has been paired over the years with rewards, with comfort, with nurturing, with all sorts of positive experiences. It is very hard to resist temptation when it is staring at you in the face."
But all is not lost. Abramson serves up several tips for surviving an encounter with a buffet table, a cruise ship smorgasbord, or a gleaming party spread.
"Clearly, when confronted with a wide range of attractive choices, that is high-risk situation," he says. "The first thing is, try to minimize those situations to begin with. Or if you are going out to eat, choose a restaurant that doesn't serve buffet style. If you are going to a party where there is a spread of food in front of you, minimize the amount of time you spend in the presence of the food, make a deliberate effort to move away."
"Likewise a little advance planning helps," he says. "If you know you are going to be confronted with a whole range choices, you may want to make a public pronouncement to your spouse that you are going to sample, say, just three different desserts, rather than go hog-wild with it."
Advance planning also includes eating less and lighter earlier in the day if you know, for example, that you will be confronted with a wide variety of choices later on that night.
"But you don't want to starve yourself because it is hard to exert any control over your eating then," he warns.
As for limiting variety in general, Abramson doesn't think that is realistic. "I don't know too many people who just eat one item," he says. "My guess is that outside of the lab settings the only people who are doing this are following some fad diet [like] grapefruit, cabbage soup, etc. Otherwise, I find it unlikely that people would eat that kind of a diet."
But Raynor says it is not all about limiting all foods, all the time.
"Another study has found, interestingly, that as the prevalence of obesity has risen in our country so has the variety in our food supply -- specifically snack, junk, and convenience foods," she says.
"To help with energy regulation, people should probably limit the variety in their diet -- specifically foods that are high in [calories] like junk food or snack foods. Obviously a person needs enough variety in their diet to get enough essential vitamins and minerals. But instead of having potato chips, cookies, ice cream, and candy in their house, they really only should have one. You don't need to have an overwhelming variety; that will help with energy regulation."