Despite the huge need for natural resources to feed a growing population, the waste of food is still considerable. In this context, a proper animal nutrition strategy could be a useful tool to reduce food losses, indeed food industry leftovers re-used as alternative ingredients in animal diets are finding a strong approval among animal nutritionists and feed producers. Ex-food, also known as Former Food Products (FFPs), are circular ingredients, well suited for re-enter in the food-chain under the form of feed, both for ruminants and monogastrics. These products, initially intended for human consumption, are no longer suitable for this purpose due to problems during the manufacturing process, packaging defects or logistical issues. They mainly consist of bakery (salty) and confectionary (sugary) products such as pasta, salty cakes, bread, biscuits, chocolates, candies and snacks. Safety of these products is guaranteed, since they are different from restaurant reflux or household waste and they are allowed by the food law (Regulation (EU) No 2017/1017) and reported in the European catalogue of feed materials. The richness in cooked starch, fats and sugars make these products suitable for young animals, especially for calves, chicks and piglets. It is well known, from previous studies carried out on post-weaning piglets, that Former Food Products have no detrimental effects on their growth performance, diet digestibility and welfare. In this regard, we decided to deeply investigate their potential effects on growth performance, diet digestibility, welfare, meat quality and in particular on the body composition to better evaluate the deposition of nutrients, no more in the post weaning phase but in the growing and finishing rearing phases. The pigs involved in the project received three different diets: I) a conventional diet (without FFPs), II) a diet in which a part of conventional ingredients was replaced by sugary FFPs and III) a diet where a part of the common ingredients was replaced by salty FFPs. To assess the pigs’ body composition, we used the dual-energy X-ray absorptiometry, a tool mainly used in human medicine. The absorption of the X- rays by the pig’s body depends on the thickness, density and chemical composition of tissues. With DXA scans we could obtain informations about the underlying tissues quantifying the fat mass, the fat free mass (lean mass) and the bone mineral content. The research project led to promising results about the body composition, growth performance, animal welfare and meat quality since there were no significant differences regarding these parameters between the pigs fed with a conventional diet and pigs which received salty or sugary FFPs. Thus, confirming that FFPs are comparable to common ingredients and a valuable source of nutrients that could be used in animal feed to reduce food waste, without detrimental effects or health risks. This research project has been carried out with the support of University of Milan and the Agroscope agronomic Research Centre of Posieux, Switzerland. A part of the results of this work will be presented in the ASPA congress (Animal Production Science, Bari, 13-16 June).