Something a little bit different for this blog, but something that in some way or form affects us all – Mindset.
I got the idea for this blog from the brilliant Peak Performance publication by Brad Stulberg and Steve Magness.
Mindset isn’t something new but in recent years has come to prominence by the brilliant Carol S. Dweck, a psychologist on the faculty at Stanford University, who proposed the mindset theory as a way to understand the effects of the beliefs that individuals hold for the nature of intelligence.
During her earlier research, Dweck identified “entity” and “incremental” theorists, based on whether individuals attributed success in tasks that required intelligent behavior to having sufficient native aptitude (entity) versus having practiced a skill and improving performance over time (incremental) 
This then led Dweck to eventually propose a theory of “mindset” to integrate a number of related ideas that she had developed over the years. 
Dweck’s mindset work differs between those with the ‘fixed’ mindset and those with ‘growth’ mindset, with these replacing her earlier work with entity and incremental theories of intelligence.
In this later work, Dweck differentiates between the individuals with a fixed mindset who believe that their qualities (such as intelligence and other personality traits) are “set in stone” and those individuals with a growth mindset, who on the other hand, believe that effort or training can change one’s qualities and traits.
Back to the Mindset Milkshake.
In 2011, a fascinating study by Crum et al., entitled ‘Mind Over Milkshakes: Mindsets, Not Just Nutrients, Determine Ghrelin Response’ was published. Crum, a clinical psychologist at Yale University has studied the placebo effect for many years and wanted to see if the placebo effect worked on food like it does on drugs.
The objective of the study was to test whether physiological satiation measured by the gut peptide ghrelin varied depending on the mindset in how an individual approaches the consumption of food. Ghrelin, is a hormone that is secreted by cells in the stomach in response to hunger. When ghrelin levels rise, it signifies that it’s time for us to eat . After eating, blood ghrelin levels drop, telling us that we are satisfied and that we do not need to eat anything else.
During the study 46 participants consumed a 380-calorie milkshake under the pretense that it was either a 620-calorie “indulgent” shake or a 140-calorie “sensible” shake on two occasions and ghrelin was measured via intravenous blood samples at 3 time points: baseline (20 min), anticipatory (60 min), and postconsumption (90 min). The participants were also asked to fill out questionnaires rating taste, hunger and dietary restraint.
The participants who consumed the “indulgent” shake reported feeling immediate satisfaction but later craved more sweeter foods later, and also experienced a greater decline in ghrelin, meaning the feedback to their brain was that they were full and satisfied, and this is what you would expect with a high calorie, sugar and fat laced milkshake – but that isn’t what the participants were consuming, they were consuming exactly the same milkshake as those who believed they were consuming the ‘healthy’ shake. In fact, Crum et al discovered that those consumed the indulgent shake responded as if their bodies had eaten three times more, so what the participants believed about their shake (or their mindset) came true. If they felt that the shake the had consumed was fattening the believed then they had eaten more and their ghrelin levels dropped three times more.
Crum et al., argued that much like placebo effects, alterations in mindset—what one believes and expects to be eating—have the potential to elicit a seemingly inappropriate sense of satiation, and while they concluded that additional research is required to understand better how psychological factors influence the biological impact of food, we cannot deny the influence of mindset on our physiological state.
Dweck’s work has proven that the way we think about the world (fixed or growth) has a huge effect on what we do in the world.
So here is my question:
If training and nutrition can influence our physiological state are we missing out by ignoring the influence of mindset?
- Dweck, C. (1999) Self-theories : their role in motivation, personality, and development. Philadelphia, PA Psychology Press.
- Dweck, C. (2017) Mindset – Updated edition: Changing the way you think to fulfil your potential.
- Crum, A et al., Mind over milkshakes: mindsets, not just nutrients, determine ghrelin response. Health Psychol. 2011 Jul;30(4):424-9; discussion 430-1.