The growth of children in developing countries often declines with the introduction of complementary foods around the age of 6 mo and continues to decline up to 18 mo. These growth deficits are accompanied by delayed development and increased morbidity and mortality. The main cause is nutritionally inadequate and often contaminated complementary foods that typically consist of a cereal-based porridge, with little vegetables and no animal products. Such a diet is bulky, has a low nutrient density and a high content of antinutrients. Promotion of traditional household technologies such as germination and fermentation may be affordable measures to improve the complementary foods. Germination serves to reduce the bulkiness and thus increase the energy and nutrient density. Fermentation leads to hydrolysis of antinutrient phytates and hence increased bioavailability of minerals, and may also have beneficial effects on susceptibility to diarrhea. Alternative strategies include addition of vitamin C-rich foods and meat that enhance absorption of minerals, or direct enrichment of energy and nutrients by addition of animal products, such as fat, fish, meat or milk, vegetables or fruits, or a micronutrient mix.