Background: As obesity rates escalate, weight-loss interventions, including low-carbohydrate (LC) and low-fat (LF) diets, have become popular. Although both diets promote weight loss, the effect of LC and LF diets on taste preference and sensitivity is less well understood.
Objective: In this study, we sought to (1) compare sweet and salty taste detection thresholds and preferences following a 2-wk ad libitum LF diet compared with an LC diet and (2) determine whether sweet and salty taste detection thresholds and preferences were associated with body weight, body mass index, blood pressure, taste relevant taste substrates (sodium and total sugar), intake, and hunger and satiety hormones (i.e., ghrelin, leptin, peptide YY [PYY] and glucagon-like peptide-1 [GLP-1]).
Methods: We analyzed and compared taste preference and detection after ad libitum, randomized, controlled inpatient feeding study (n = 18) comparing LC (10% carbohydrate, 75% fat, and 15% protein) and LF (75% carbohydrate, 10% fat, and 15% protein) diets. Taste measures and hormone levels were measured at the end of each dietary period.
Results: We found no significant differences in taste measures between the LC and LF diets. However, we did observe a negative association between salt preference and leptin levels during both LC (rs = 0.59; P < 0.01) and LF (rs = -0.47; P < 0.05) dietary period. Salt taste preference was also negatively correlated with GLP-1 after the LF diet (rs = -0.61; P < 0.01). The results of this post-test study suggest that taste measures do not differ between 2-wk LC and LF diets.
Conclusions: The results suggest that taste measures do not differ following 2-wk LC and LF diets. However, the relationship between taste preference and hunger and satiety hormones should be explored further.This trial was registered at www.clinicaltrial.gov as NCT03878108.
Keywords: hunger and satiety hormones; keto diet; low-carbohydrate diet; low-fat diet; taste detection threshold; taste preference.
© 2025 The Authors.