Obesity has become a major health problem in humans. Though obesity is not common in farm animals, food restriction is often used to maintain low feeding costs and optimal performance of, for example, pregnant sows (the parent stock of meat pigs). Food restriction may impair the welfare of these animals due to hunger and frustration of feeding motivation. Knowledge on the regulation of satiety is thus crucial to aid in the control of food intake in humans, and to improve welfare in food-restricted farm animals.
Dietary fibres are believed to enhance satiety, but the effectiveness varies with the physicochemical properties of the fibre sources concerned. Therefore, the objective of this thesis was to identify whether and how dietary fibres with different physicochemical properties, such as bulkiness, viscosity, gelling and fermentability, affect satiety in the domestic pig, which was used both as a model for humans and as a target animal. It was concluded that fermentable fibres are more satiating than viscous and bulking fibres.
The satiating effects of fermentable fibres are likely mediated by an increased production of short chain fatty acids and a reduced supply of glucose. Under free feeding conditions, gelling and fermentable fibres did not reduce long-term food intake and total body weight gain, yet, colon empty weight was increased and carcass growth was reduced. This implies that changes in body composition and intestinal weight or content, rather than body weight and body mass index (BMI) alone may be relevant to fully acknowledge the effects of fibres to aid in maintaining or promoting healthy body weight in humans.