Shrink your plate, silverware, and portion size and there’s a good chance you’ll eat less, potentially a lot less, suggests a recent analysis of studies. The Cochrane review of the research is the most conclusive to date that adults eat more when offered more, whether that food comes in a package or a dish.
If US adults were to consistently move from the larger-sized portions, packages and plates to the smaller versions across the entire day, we could reduce average daily calories by 22 to 29 percent – up to 527 calories – the authors estimate. In the United Kingdom, where the authors are from, adults could reduce calories by 12 to 16 percent – equivalent of up to 279 calories per day.
The review offers one potential way for healthier eating and weight control. Being a healthy weight is one of the most important ways to reduce cancer risk, along with heart disease and other chronic conditions.
Review authors analyzed 69 studies they identified that all compared two groups of people, each presented with a different size of a portion, package, plate or utensil. The studies, which spanned from 1978 to 2013, had to meet a set criteria for study design, bias and other factors. All the studies were conducted in high-income countries, with most done here in the United States.
For both kids and adults, people exposed to larger-sized portions, packages, individual units or tableware consistently eat more compared to when they are given smaller versions. The older participants were, the more they ate when given larger sizes.About half of the studies manipulated portion size. Adults – but not children – ate more when served larger portions compared to smaller ones.Adults – but not children – ate more when presented with larger plates, bowls and other tableware compared to smaller ones.
Many of these studies lasted only a day and all were short term, which means further research is needed to see if the short-term changes seen would last. Researchers highlight a range of ways that manufacturers, governments and individuals could reduce the sizes, such as giving upper limits on serving sizes of fatty foods, desserts, and sugary drinks, or placing larger portion sizes further away from shoppers to make them less accessible.
And more research is needed to see if reducing portions in relatively small amounts can be as effective in reducing food consumption as reductions at the larger end of the range.
(The authors had also set out to analyze alcohol and tobacco but they only found three relevant tobacco studies and none for alcohol.)