Here is an interesting study that I came across via the New Scientist.
IF YOU want to lose weight, convince yourself that everything you eat is highly calorific. It could lower your levels of a hunger hormone, potentially suppressing your appetite.
Alia Crum at Yale University and her colleagues gave 46 healthy volunteers the same 380-calorie milkshake but were told it was either a sensible, low-calorie choice or an indulgent, high-calorie one. The team also measured levels of ghrelin - a hormone released by the stomach when we are hungry - before and after participants drank the shake.
Ghrelin levels have been shown to spike half an hour before mealtimes and return to normal after eating.
Volunteers who thought they had indulged showed significantly greater drops in ghrelin levels than those who thought they had consumed less. The authors suggest that merely thinking that one has eaten something unhealthy can quell hunger pangs and perhaps help curb overeating
Here is the abstract of the paper:
Mind over milkshakes: Mindsets, not just nutrients, determine ghrelin response.
Objective: To test whether physiological satiation as measured by the gut peptide ghrelin may vary depending on the mindset in which one approaches consumption of food.
Methods: On 2 separate occasions, participants (n = 46) consumed a 380-calorie milkshake under the pretense that it was either a 620-calorie “indulgent” shake or a 140-calorie “sensible” shake. Ghrelin was measured via intravenous blood samples at 3 time points: baseline (20 min), anticipatory (60 min), and postconsumption (90 min). During the first interval (between 20 and 60 min) participants were asked to view and rate the (misleading) label of the shake. During the second interval (between 60 and 90 min) participants were asked to drink and rate the milkshake.
Results: The mindset of indulgence produced a dramatically steeper decline in ghrelin after consuming the shake, whereas the mindset of sensibility produced a relatively flat ghrelin response. Participants' satiety was consistent with what they believed they were consuming rather than the actual nutritional value of what they consumed.
Conclusions: The effect of food consumption on ghrelin may be psychologically mediated, and mindset meaningfully affects physiological responses to food