Perceived hunger, palatability, and adherence: A comparison of high- and low-fat diets

To investigate whether there is a difference in palatability and perceived hunger between high- and low-fat diets, and furthermore to see if any such differences are correlated with the degree of adherence to a diet and with weight reduction.

Randomised, parallel, two-arm, open-label 10-week dietary intervention study comparing two hypocaloric (-600 kcal/day) diets with a fat energy percent of 20-25 or 40-45.

Obese (BMI ≥30 kg/m(2)) but otherwise healthy adult subjects (n = 100).

Perceived hunger, palatability of diet, difficulty of following dietary instructions and adherence to diet by visual analogue scales, and body weight loss.

There were no significant differences between the low- and high-fat groups in perceived hunger, palatability, difficulty of following instructions, nor adherence to the diet. There were significant trends towards lower perceived hunger during the trial [F(1, 86) = 49.99, p < .001], towards increased perceived adherence [z = 2.851, p = .004], and towards less perceived difficulty of following both diets during the second and third week [F(1, 86) = 23.51, p < .001]. Median weight loss was 7%. The patients who reached at least median weight loss decreased their perceived hunger significantly more than the group who did not [F(1, 85) = 4.12, p = .046], and had less difficulty of following instructions throughout the treatment period [F(1, 85) = 4.35, p = .040]. There was a strong negative correlation between perceived hunger and palatability [-.55] as well as between difficulty of following instructions and palatability [-.45], and a strong positive correlation between difficulty of following instructions and perceived hunger [.63] with both diets.

The perceived hunger during the diet intervention and palatability of the diet are important factors for succeeding with weight reduction. The fat proportion of the diets was not important for determining perceived hunger and palatability. These findings suggest that the ability to compose a palatable and satiating diet may be important for successful weight reduction.