Purpose: Consuming 30 g of nuts/day is recommended to reduce chronic disease. However, nut consumption appears far from ideal among several populations. A potential strategy to increase consumption is to add nuts to a staple, for example, bread. Whether the health benefits and acceptability of nuts persist in this form is currently unknown. Thus, we examined the effects of consuming three nut-enriched breads on postprandial glycaemia, satiety, gastrointestinal tolerance, dietary intakes, and acceptance.
Methods: In this controlled, crossover study, 32 participants were randomly allocated to receive one of four breads for 8 days each. Three breads contained either 30 g of finely sliced hazelnuts, 30 g semi-defatted hazelnut flour, or 15 g of each (amounts per 120 g bread) and were compared with a control nut-free bread. Blood glucose response was measured over 120 min, along with ratings of gastrointestinal discomfort. Appetite ratings and diet diaries were completed during each treatment period.
Results: Area under the blood glucose curve was significantly lower for the nut breads compared to the control bread (all P < 0.001), with no significant differences between the nut breads (all P ≥ 0.130). There were no significant differences in satiety (all P ≥ 0.135) or gastrointestinal symptoms (all P ≥ 0.102) between the breads. Acceptance was highest for the finely sliced hazelnut bread. Furthermore, consuming hazelnut-enriched bread improved diet quality, increasing monounsaturated fat, vitamin E, and dietary fibre intakes.
Conclusion: Bread appears to be an effective and acceptable vehicle for increasing nut consumption, resulting in improved postprandial glycaemia and diet profiles. Long-term studies are now required.
Keywords: Acceptance; Appetite; Gastrointestinal tolerance; Nuts; Postprandial glycaemic response; Satiety.