Last fall, Researchers at the University of Pennsylvania published a study exploring the relationship between portion size and food consumption. They found that people tend to consume more when given larger portions. From the abstract:

People seem to think that a unit of some entity (with certain constraints) is the appropriate and optimal amount. [...] We propose that unit bias explains why small portion sizes are effective in controlling consumption; in some cases, people served small portions would simply eat additional portions if it were not for unit bias. We argue that unit bias is a general feature in human choice and discuss possible origins of this bias, including consumption norms.

The article — available online in PDF form — argues that the American struggle with obesity may be because we consume larger portion sizes than, say, the French.

What does this have to do with personal finance?

In the short-term, you can save money by simply eating less. Consuming smaller portions can help you stretch your food dollar. In restaurants, split your meal with another person, or take some of it home for later. At home, prepare smaller servings, or freeze the extra for future use.

Consuming smaller portions can also save money in the long-term. Health-care costs are an important financial consideration. Weight-related problems can have dramatic effects on a person’s physical condition, increasing the risk of heart disease, diabetes, and other ailments. A few years ago, I tore up a knee so that it required expensive surgery because I was overweight and out-of-shape.

Reducing portion size is a little thing, but little things add up.

[via BPS Research Digest]