How sweetness intensity and thickness of an oral nutritional supplement affects intake and satiety

Oral nutritional supplements (ONS) can be used to improve the nutritional status of malnourished patients, but their effectiveness depends on adequate intake. This is not always achieved due to the disliked flavour and satiating properties of ONS. The aim of this study was to investigate the effect of sweetness intensity and thickness on intake and sensory sequential profile of an ONS. It was hypothesized that lower sweetness intensity and thickness would decrease oro-sensory stimulation and satiety, improve the sensory profile, and thus, improve ONS intake. The effect of sweetness intensity and thickness on intake and satiety was investigated using a 2 × 2 design (low-high-sweetness and thin/thick). Participants (n = 36) consumed each ONS to satiation. Each ONS was identical in macronutrient and calorie content. Appetite and thirst were measured throughout the morning of the test. Additionally, an expert sensory panel (n = 11), performed a sensory sequential profile of each ONS. No effect of sweetness intensity was found. Results showed that 33% more of the thin, compared to thick, ONS was consumed, without affecting satiety. Furthermore, mouth-drying first increased, up to a consumption volume of 300 ml, and then decreased, independent of sweetness intensity and thickness. In conclusion, this study showed that an ONS with lower thickness increased intake in healthy adults, without affecting satiety. This implies that, for ONS, attention should not be solely focused on nutritional content. Instead, a sensory-nutrition approach is recommended that balances nutritional content with oro-sensory cues. This proof of concept should be further investigated with malnourished older adults.