Have your clients ever described a time when they had the opportunity to eat a high-calorie snack food – and had trouble resisting? Psychologically, even noticing that type of food can set the mind off, as it starts thinking about the taste, texture and pleasure of eating the food – and that’s before they’ve even had a mouthful! It should not come as a surprise that these types of foods present a significant challenge for people who are working towards weight loss.
Portion size, and the portion size effect
Another significant factor that affects weight loss is that snacks of this type have gradually increased in portion size over the last 30 years. The problem is the portion size effect: people tend to eat more food from a larger container or serve than a smaller one. It is believed that the size of the portion is a psychological cue as to how much to eat.
Dutch researchers were interested to understand if a mindfulness exercise could change the way a person eats a particular type of snack food (in this case, chocolate chip cookies). To test the idea, participants from a university with an average body mass index of 22.3 were allocated to one of four groups:
  •  Small portion size and control intervention
  •  Large portion size and mindfulness intervention
  •  Small portion size and mindfulness intervention
  •  Large portion size and control intervention
The mindfulness intervention
The mindfulness intervention was a 14-minute pre-recorded body scan meditation: a process where the participant had their attention guided from one part of their body to the next. The control group listened to a 14-minute excerpt from an audio book (the subject matter was not related to food, weight or the body).
Food and portions
Participants were told that the next stage was a separate experiment to understand the consumer experience. They were then served either a small (247.5 cal) or large (742.5 cal) portion of chocolate chip cookies, a small glass of water, and provided with a survey form listing questions about the cookies.
Participants were told they could eat as many cookies as they wanted. Consumption of food was calculated by comparing the weight of the plate of food before and after the experiment.
Across all groups, there was no significant difference in BMI, age or hunger. The only discernable difference between the four groups was that participants in the groups which received the larger portions of cookies reported higher feelings of guilt and concern for dieting. People who received the larger portion of cookies ate 83 more calories than those who received the smaller portion. This finding applied to the group that received the mindfulness intervention, as well as the group that received the control and shows the power of the portion size effect!
Mindfulness and hunger
Hunger was also measured in the study. People with high levels of hunger ate more food overall, but the participants who received the mindfulness intervention consistently ate 175 calories of cookies – whether hungry or not. By comparison, participants in the control group who had high levels of hunger ate an extra 67 calories than those in the same group who were not hungry.
What this means for your weight loss clients
Although this research shows that a mindfulness intervention does not impact the portion size effect, it does appear to assist people who are hungry to moderate their calorie intake. The results also suggest that the portion size effect (or reliance on external eating cues) is not affected by a person’s hunger or satiety.
This research is fascinating. You can use the findings in two ways:
1. Remind your clients to pay extra attention to portion sizes, and to avoid larger serves or portions wherever they can because of the power of the portion size effect; and
2. Teach your clients to use mindfulness techniques when they are very hungry, as a technique to prevent eating more food than they would otherwise consume.
Marchiori, D., & Papies, E. K. (2014). A brief mindfulness intervention reduces unhealthy eating when hungry, but not the portion size effect. Appetite, 75(0), 40–45.