Americans are known for excess, and food is not excluded. Portion sizes of food are often large and include more than one serving, which may be contributing to the increased prevalence of obesity in the country. Recent studies have examined the effect of portion size on amount of food consumed in an attempt to prove this theory, however results are conflicting.
One study, in which experimenters served men increasing portions macaroni and cheese, found that participants ate more food when portions were increased by as little as 27 percent. Although intake increased with the amount of food presented, ratings of fullness after the meal were not affected. This suggests that portion size may influence hunger and the feeling of satisfaction after a meal, according to researchers, because as more food was offered, it took longer for participants to reach satiation.
Conversely, in another study researchers manipulated portion sizes of lasagna and found that men consumed a substantially greater amount of food only when portion size was at least doubled. These two studies show that people responded to both small and large portion size increases.
Serving method may influence whether portion size affects food intake, the report notes. In studies where people ate more with greater portion sizes, people were given predetermined amounts of food, which they ate directly from the plate it was served on. On the other hand, when people themselves determined the amount of food on their plates, their intake was constant.
Previous studies have shown that when adults serve themselves, the amount of food taken remained constant and they ate a relatively consistent amount of food. In the study where participants were served, the amount of food in the serving dish varied, and participants’ intake of food varied. Researchers hypothesized that portion size would be influenced by who, experimenter or participant, determined the amount of food on a plate.
Another recent study showed that when young children were served food, they consumed about 25 percent more food than when they helped themselves. It is not clear why the adults and children differed in their responses to portion size when they served themselves. Researchers speculate that children may be encouraged to “clean their plates” and therefore ate more, or that they may have used their own hunger as a guide of how much food to take when serving themselves. Adult participants, however, were influenced by portion size even when they served themselves.
This may be explained by a recent survey in which 25 percent of those polled agreed that the amount of food they are served helps them decide how much food to eat. Moreover, in another survey 67 percent of participants said that they finish their entrees when eating out all or most of the time. As many restaurants serve large portions, researchers not that this could be problematic and recent studies have shown a link between body weight and frequency of consuming meals from restaurants.
Researchers note that future studies should examine whether specific factors, such as age, food type or packaging, influence a person’s tendency to alter food intake with portion size. Additionally, educating people on appropriate portion sizes may be effective in the treatment and prevention of obesity.
American Journal Clinical Nutrition December 2002 76:1207-1213
Controlling the size of your serving is a simple — yet highly effective — method to control your weight.
It certainly is not the only or the major factor to consider, but it is something that is easy to pay attention to as you weave yourself through the social challenges of eating out, where you are not in control of your serving size.
The massive decrease in food costs, shown by the fast food industries’ lowering of prices, will perpetuate this vicious cycle as offering junk food at lower prices will make it easier for you to become addicted to it.
However, if you are applying the principles in the nutrition plan with special attention to following a program for your Metabolic Type, you will be far more likely to be successful at maintaining your optimal weight.
When you are eating for your Metabolic Type you will not have food cravings, so reducing your portion will not be such a challenge. You can split your meals into five or six smaller portions, and you will be far less hungry.
If you are having food cravings then you need to readjust your food choices as discussed in the highly recommended book, The Metabolic Typing Diet. Typically this involves shifting the ratio of protein to fat to carbohydrate once you have determined what types of food your body is designed to eat.
So it may have absolutely nothing to do with the type of food you are eating, but with the relative percentage of each food you are eating.
This is a very exciting concept as there are many factors that you can change if you aren’t having success. Once you adjust one or more of them your likelihood of finally succeeding in optimizing your weight is quite high.
However, even with the perfect diet it is important to recognize that emotional issues may cause a major self-sabotage for you.