The psychology of how we make our food choices continue to fascinate. A number of studies indicate that how we perceive food greatly determines the production of hormones that influence how much we will eat.
For instance, experiments show that if we’re led to believe something about a food or portion size, we tend to believe it, and the body responds as though it were true. According to the results of a study presented at the 2011 Annual Meeting of the Society for the Study of Ingestive Behavior (SSIB), subjects who were told that their portion sizes were larger than the actual size felt satiated for a longer period of time after eating. The notion that our appetite is easily influenced by suggestion was corroborated by a 2006 Cornell University study which found that participants using a larger bowl ate 30 percent more than those using a smaller bowl, that those using a larger utensil ate 15 percent more, and those participants both a larger bowl and utensil ate a whopping 57 percent more than those using a small bowl and small utensil, however the participants who ate more believed they were eating approximately the same sized portion as those who ate less!
These results validate experts’ suggestions to use smaller plates for everyday meals for portion control.
The study presented at the SSIB also found that a person’s memory of how satisfied he or she will feel after eating a certain meal also plays a role in appetite control. This information could provide another clue towards why diets fail. If we have a preconceived idea about how filling we think a food will be before we eat it, choosing foods labelled “light” might lead us to expect that we won’t feel satisfied, causing us to eat more afterwards.
In another study, researchers had 38 men and women between the ages of 24 and 30 eat the same three-course meal on two separate days. The meal consisted of salad, macaroni with meat sauce, vegetable lasagna and raspberry pudding.
On the first day, the meal was to be consumed within 30 minutes. On the second day, the meal was eaten over a longer period of time, with up to 25 minutes in between courses.
The subjects were interviewed and blood samples taken before, during and after the meal that measured hormones involved in appetite signalling, including ghrelin, a hormone that increases when you’re hungry.
The researchers found that satiety hormones spiked more rapidly during the 30 minute meal and gradually increased during the staggered meal.
This study supports the grazing eating style. Grazing, or eating multiple small meals and snacks throughout the day, keeps your appetite under control, metabolism high and portion sizes small (since you’re never hungry enough to eat a large meal). Of course, grazing on unhealthy foods (including fast food, junk food or processed food) can cause our health to deteriorate and will likely lead to weight gain. For healthy grazing, prepare snacks ahead of time, such as trail mixes, sliced veggies and healthy dips, fruit, yogurt, and healthy energy bars (read labels before buying).
Surprisingly, this same study also found that when subjects were offered unhealthy but tasty treats following their meal, those who ate the staggered meal ate only 10 percent fewer snack calories than those who eat their meal more quickly. This just goes to show that taste and the availability of tempting foods trumps appetite, overriding signals about satiety and when to stop eating.
The interesting finding gives credence to yet another study, published in Journal of Functional Foods, which found that when buying food, knowledge about the nutritional quality of a food is not as influential as taste and price, and packaging. The participants were not interested in purchasing food that did not taste good, regardless of its benefits to health.
The researchers also found that consumers deem the health claims made by large food companies to be accurate and trustworthy.
References:
Wansink, B., van Ittersum, K., Painter JE., (2006) “Ice cream illusions: bowls, spoons, and self-served portion sizes” Am J Prev Med¸31(3):240-3.
Lemmens, SG, Martens, EA, Born, JM, Martens, MJ, Westerterp-Plantenga, MS., (2011) “Staggered meal consumption facilitates appetite control without affecting postprandial energy intake” The Journal of Nutrition, doi: 10.3945/?jn.110.133264.
Lalor, F., Madden, C., McKenzie, K., Wall, PG., (2011)“Health claims on foodstuffs: A focus group study of consumer attitudes” Journal of Functional Foods, doi: 10.1016/j.jff.2011.02.001.
