Protein Adequacy across Meals in Dutch Elite and Sub-Elite Athletes

Adequate daily protein intake does not necessarily ensure sufficient per-meal level of essential amino acids, particularly when meals rely on plant protein sources. We evaluated meal-level protein quality in elite and sub-elite Dutch athletes using the Meal Protein Quality Score (MPQS). This secondary analysis used non-consecutive 24-h dietary recalls from the Dutch Sport Nutrition and Supplement Study (2012–2015). MPQS was calculated for breakfast, lunch and dinner, assuming a per-meal protein target of 0.4 g/kg. Data from 503 athletes (299 men, 204 women) were analyzed. Median MPQS was lowest at breakfast (71 [IQR 43–109]) compared with lunch (93 [48–146]) and dinner (147 [85–219]). Accordingly, 71% of breakfasts and 54% of lunches had an MPQS < 100, meaning that at least one essential amino acid did not meet the meal requirement, while more than one-quarter of dinners also remained below this threshold. When considering meals containing meat and/or fish, MPQS values were higher across meals (breakfast: 94 [60–136]; lunch: 117 [68–169]; dinner: 174 [120–238]).Vegetarian meals showed lower MPQS values across meals, and fully plant-based meals rarely met the adequacy threshold of MPQS > = 100 (breakfast: 25 [15–40]; lunch: 21 [6–34]; dinner: 21 [10–31]). Network analysis identified energy intake as the strongest positive correlate of MPQS, whereas breakfast meals and a higher proportion of plant protein were negatively associated. In fully plant-based meals, nuts and seeds, savoury spreads, and meat/dairy substitutes were the main positive contributors, and several food-group combinations improved MPQS. Despite generally adequate daily protein intake, meal-level protein quality is frequently insufficient in elite and sub-elite Dutch athletes. Optimization and complementary plant-protein combinations may help athletes achieve essential amino acid adequacy at each main meal.