Fiber in Animal Nutrition

65 Low-calorie diets Thus, three studies (Janowitz and Gross- man, 1949; Jewell et al., 2007; Yamka and Riesen, 2008a) indicate that putting out high-fiber food once daily and taking it away after 45 minutes induces some weight loss. When obese dogs in home settings were fed standardized, restricted amounts of available energy for on average six months they lost more body weight when the diet was high instead of lower in crude fiber (German et al., 2010; Fritsch et al., 2010). So far, this diet effect cannot be explained. There is no evidence that high-fiber foods induce satiety. Dogs with time-limited access to a wet food with added cellulose could not meet their maintenance energy requirements, but when given the cellulose-free wet food as subsequent meal they raised drymatter intake (Dobenecker andKienzle, 1998).When high- fiber foods were fed in restricted amounts, dogs generally consumed at least two-fold their daily energy allowance in the form of challenge meal offered at three or six hours after introduction of the high-fiber food (Weber et al., 2007; Butterwick et al., 1994; Butterwick and Markwell, 1997; Bosch et al., 2009). 5.4.2 Low-calorie diets for cats When faced with caloric dilution of their diet with cellulose, free-fed cats continue to consume the same weight of solid food as has been shown in experiments lasting up to about 20 days (Kanarek, 1975; Goggin et al., 1993; Prola et al., 2010). The same was seen for mixing a wet food with cellulose- rich peanut hulls (Fekete et al., 2004) and for cats with unlimited access to a low- or high-fiber dry diet from 2 pm to 8 am daily (Servet et al., 2008). When cats with mean body weight of 3.2 kg were given ad libitum access to two fiber-enhanced, dry diets for 16 weeks food intake and body weight were left unchanged (Yamka and Friesen, 2008b). In a research facility, cats with stabilizedmean body weight of 6.6 kg were switched from a regular dry food to a fiber-enhanced rich food which they consumed without restraint for 8 weeks (Floerchinger et al., 2015). The high-fiber diet did not affect food intake measured in grams, but it reduced body weight by 0.57% per week. Similar rates of weight loss can be seen in the home setting when cats are fed restricted amounts of food for weight reduction (German et al., 2008; Bissot et al., 2010). When fed equal quantities of weight, over- weight cats lost more weight on a fiber-enhan- ced food compared with a regular dry food (Michel et al., 2005). When fed comparable, restricted quantities of calories, cats had si- milar weight loss on a low- or high-fiber wet diet and were perceived by their owners to be equally hungry throughout the day (Cline et al., 2012). One study (Bissot et al., 2010) found that the type of fiber in high-fiber dry diets affected hunger behaviors of cats during energy restriction. However, feeding practices differed for two high-fiber diets and the behavioral effect size was small, making practical significance doubtful. It is unlikely that cats compromise ener- gy intake on a high-cellulose diet because diet palatability is diminished or satiety is enhanced. If low palatability plays a role, dry matter intake on a wet food would be expected to be inversely related to the level of cellulose, but this was not observed (Prola et al., 2006). The feeding of a high- or low-fiber dry diet with similar taste, as measured in a palatability trial, resulted in similar bulk intake (Servet et al., 2008). After consuming a wet food mixed with cellulose, cats were © ERLING Verlag