3 Strategies To Overcome the Portion Size Effect


You’ve probably heard that increasing portion sizes are making us eat more—a concept researchers call the “portion size effect”. Bigger portions promote bigger bites, and bigger bites mean less exposure time. Sensory-specific satiety cues, which turn down the feelings of pleasure we get from eating the same thing for a while, won’t kick in to stop us when we inhale our food. 

According to a meta-analysis, the portion size effect is so strong that doubling the amount of food on your plate can lead you to eat 35% more! So, are we helpless or can we overcome the power of big portions? An intriguing study from Appetite suggests that we can in fact manipulate the portion size effect to prevent overeating. Today we’re discussing these findings and dishing 3 easy strategies to overcome the portion size effect.

Portion Size Effects Vary

The present study was conducted as 3 separate experiments. In the first experiment, participants were offered brownies to snack on while watching a video. Each person was randomly assigned a different portion size, manipulated in terms of the size of the brownies offered (unit-size) and the number of brownies (unit-number). The total portion size given to each person ranged from 8g to 256g.

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On average, participants given a 32g portion of brownies would consume 65% if it was served as four small pieces, while those given just one large piece would eat 80%.

Vandenbroele, Jolien, et al.

Not surprisingly, the results showed that these people ate more when served more, but what’s really interesting is that the portion size effect was stronger when participants were given fewer large brownie pieces compared to those eating the same portion size comprised of many small brownie pieces. On average, participants given a 32g portion of brownies would consume 65% if it was served as four  small pieces, while those given just one large piece would eat 80%. The second and third experiments looked at participants’ quantity perceptions of portions (i.e., how large or small they perceived differing portion sizes to be). Participants viewed portions made up of a greater number of food units to be more than those made up of fewer, larger units. The findings of study 3 confirmed that perceived quantity mediates the portion size effect, meaning you’re probably less likely to overeat what you recognize to be too big a portion for you. This study did not examine personality traits that could impact this relationship, however, so this is not true for everyone.

3 Strategies You Can Try Today

  1. Gauge your portion size before you eat. Ask yourself: Does this look like too large a portion for me? Is this more food than I typically need to feel satisfied? 

  2. If you recognize that your portion is large, consider splitting the meal into two portions and share or save one to enjoy the next day.

  3. Opt for snack foods packaged as several bite-sized pieces (like individually wrapped chocolates over full-size chocolate bars) to slow down your eating.

If you’re looking for personalized support for weight management, book a free dietitian appointment here.

Ryan Stallard