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.