Few advances would contribute more to the growth and well-being of infants and children in the developing world than the making available of acceptable staple foods that are easy to grow and process, nutritionally complete enough to serve as the major weaning food, and safe without refrigeration. High-fat quality-protein maize (QPM), grown in Mexico, had > 10% of its energy as well-balanced protein and > 15% as fat. When it was fed to six recovering malnourished infants to provide 85-88% of dietary energy, all of 9.8% protein calories, and all of 13.5% fat calories, it was easily consumed and tolerated. In comparison with a fiber-free, casein-based diet, fecal wet and dry weights of children consuming two varieties of high-fat QPM were three to four times greater, and apparent digestibilities of energy were 86 +/- 3 and 86 +/- 4 versus 97 +/- 1%, of carbohydrate 88 +/- 3 and 89 +/- 5 versus 100%, and of nitrogen (N) 77 +/- 4 and 75 +/- 4 versus 89 +/- 2% of intake. High "biological values," 43 +/- 10 and 46 +/- 13 versus 43 +/- 10% of absorbed N, led to comparable apparent N retentions: 33 +/- 8 and 35 +/- 9 versus 38 +/- 9% of intake. Results were similar to those from earlier studies with Peruvian QPM with a typical fat content. Fat absorptions from QPMs were nearly complete, equal to those from separated vegetable oils in the casein diet. Breath H2s were suggestive of significant colonic salvage of incompletely digested maize carbohydrates.