Food Reinforcement Value, How Much Does it Matter?

“What would you do for a Klondike bar?” What’s maybe the most well-known ice cream jingle, embodies a trait that behaviorists called food reinforcement value. Food reinforcement is defined as how hard a person will work to get access to food (assuming they are not actually hungry). Today at the 30th annual meeting of The Obesity Society, Leonard Epstein, PhD discussed this in a talk called Relative Reinforcing Value of Food, Impulsivity, and Food Choices: Associations with Energy Intake and Weight Gain. Food reinforcement can be incredibly strong, he says, and began by referencing animal studies that show evidence of food being more reinforcing than heroine or cocaine.

Dr Epstein pointed to studies, including his own recent work, that show:

  • obese adults find food more reinforcing that non-obese adults
  • food reinforcement is related to greater body fat in adolescents
  • overweight children find snack foods more reinforcing than lean children.
  • overweight children respond more to food rewards than non-food rewards, but lean children respond more to non-food reward than food.
  • lean adults were studied, and their food reinforcement values accurately predicted how much weight they would gain in the future.

In addition to the tie between food reinforcement value and obesity, there’s another factor that works close with high food reinforcement value to create a dangerous combination: poor impulse control, or difficulty delaying gratification. Citing the Stanford marshmallow experiment from 1972 – where researchers asked kids ‘would you like one marshmallow now, or two marshmallows later?’ – Epstein said that 40 years later, kids who chose ‘one marshmallow now’ (a decision tied to low impulse control, or the likelihood of choosing instant gratification) are more likely to be obese than their ‘two marshmallows later’ counterparts. The trait of high impulsivity remained through the decades of those children growing up.

Although impulse control can make a person more susceptible to obesity, it can have an effect on food reinforcement in a postive way too. Epstein said that a study showed that people with high impulse control (likely to make the choice to delay gratification) combined with high food reinforcement, were just as likely to be lean as people with low food reinforcement values. This discovery is interesting because it leads to the potential for helping people with impulse control to override a high food reinforcement value, which may be easier than trying to alter a person’s food reinforcement value itself.

This challenge – helping people modify impulse control – is one Dr Epstein is working on: How can we bring the future benefit (e.g. losing weight), to the immediate choice (e.g. choosing a healthy vs. unhealthy food option at a restaurant)? His group is designing methods for helping people make the choice to delay benefits. In one result he presented, from people who did exercises called episodic future thinking, he found that people who did these exercises ate less food in a lab study (about 800 calories), than those who had not had the training (about 1100 calories). With the success his group is seeing in these early experiments, the next questions he’s hoping to answer is how often does someone need to practice the techniques he’s teaching in order to retain the benefit.

Related Reading: The Nature and Nurture of Liking Food


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