Insulin resistance is associated with elevated activation of food reward, which should be associated with an increased reinforcing value of food. Research has also shown that sugar is a macronutrient strongly associated with reward and reinforcing value of food. This research is designed to assess whether insulin resistance is associated with a stronger preference for sugar-sweetened, thus elevating blood glucose responses in obese people with varying degrees of insulin resistance.
Thirteen people with obesity (body mass index, 39.1 kg/m2; range, 30.0–45.1 kg/m2) with varying degrees of insulin resistance (Homeostatic Model Assessment of Insulin Resistance, 5.2; range, 0.7–11.6) consumed novel flavored-colored yogurts that were sweetened with either sugar or monkfruit daily for 6 days to assess whether when given the choice of sugar-sweetened versus monkfruit-sweetened yogurts to consume, participants preferred sugar-sweetened yogurts.
Participants consumed a greater amount (p = .009) and percentage (p = .04) of sugar-sweetened yogurt earned than monkfruit-sweetened yogurt. The percent of sugar-sweetened versus monkfruit-sweetened yogurt consumed in relationship to amount earned was related to insulin resistance (r = 0.64, p = .019), glycated hemoglobin (r = 0.61, p = .027), insulin (r = 0.58, p = .007), and glucose (r = 0.56, p = .048).
Insulin resistance is associated with preference for sugar-sweetened foods in participants with obesity, which may make it hard to make dietary changes. Research is needed to assess whether treatments that improve insulin resistance also change the preference for sugar-sweetened or high-glycemic-index foods.