Influence of Dietary Fat and Carbohydrate on Food Intake, Body Weight and Body Fat of Adult Dogs

Abstract

Certain strains of rodents become fatter when fed high-fat rather than high-carbohydrate diets while other strains are able to consume a high-fat diet without an appreciable increase in body fat content (1-4). The obesity prone rodents are less able to regulate their food intake when fed a high-fat diet; additionally, consumption of a highfat diet has also been shown to increase the efficiency of energy utilization in pair-fed rodents ( 5 , 6). Less attention has focused on the interrelationship of the dietary fat to carbohydrate ratio and the development of obesity in other species.The influence of the dietary fat to carbohydrate ratio on body weight and body fat has been studied in young growing dogs (7). The fat-free body weight gain was not influenced, but accumulation of body fat tended to be elevated in dogs fed high-fat diets. Body fat averaged 29% of body weight in the young dogs fed diets with more than 50% of energy from fat while the body fat content averaged 23% in dogs fed the diets which contained less than 50% of energy from fat. The dogs were only 10months-old at the end of the 8-month study; had the diets been fed to adult dogs, body fat content might have been altered to a greater extent.The purpose of the present study was to examine the influence of a high-fat diet ( 5 1 % of energy from fat) and a high-carbohydrate diet (59% of energy from carbohydrate) on food intake and on body weight and body fat changes in adult dogs. Dogs were fed these diets for 25 weeks. Materials and methods.Three-year old female beagle dogs2 were housed in individ-' ual cages with raised floors. Lights in the temperature-controlled (22-23") room were on from 7 A M to 7 PM and off from 7 PM to 7 AM. Prior to the present study the dogs were fed approximately 750 kcal daily for 110 days. The composition of this nutritionally adequate (8) canned diet has been described previously (Table I, Diet 6 in Ref. 7). The dogs approximately maintained their weight during this 11 0-day period. Food and water were offered ad lib. during the present study. Dogs were fed once daily. Body weights were recorded weekly.Two semipurified diets were prepared; one diet was high-fat and the other highcarbohydrate. Each diet was formulated to contain 20% of energy from protein. A p proximately 50% of the protein in the diets were derived from isolated soybean protein and 50% from beef kidneys. Corn oil (7% of energy) was added to provide a source of essential fatty acids. Corn starch and tallow were added to provide the desired carbohydrate to fat ratio. A mineral and vitamin supplement3 and cellulose (6% of dry matter) were added to each diet. The diets were canned.At monthly intervals samples of each diet were obtained and analyzed for moisture by drying to a constant weight at 50°, for gross energy with a bomb calorimeter and for nitrogen by the Kjeldahl procedure. Protein was determined by multiplying the Vitamin premix was added at the level of 550 mg/ kg diet. The vitamin premix contained per g: vitamin A-5344 IU; vitamin D3 = 132 IU; vi...

The contribution of animal models to the study of obesity

“…This work has been previously comprehensively reviewed (West & York 1998), hence we will spend less time on these studies here. The most extensive studies have been made in rodents and non-human primates, although other studies have been made in other species such as hamsters (Wade 1982), squirrels (Faust & Mrosovsky 1987, Dark et al 1992, pigs (Pond et al 1985), dogs (Romsos et al 1976(Romsos et al , 1978 and sheep (Tolkamp et al 2007). Two types of response have been observed when animals are given high-fat or high-fat high-sucrose diets: some species and strains gain weight, but others do not.…”

Energy and Water

“…[1][2][3] Energy density or caloric density refers to the concentration of energy in a given quantity of food (see p. 6). When allowed free access to a balanced, moderately palatable diet, most dogs and cats will consume enough food to meet, but not exceed, their daily energy needs.…”

Efeito de dois alimentos comerciais secos e dois fornecimentos no consumo alimentar, pesos vivo e metabólico, escore corporal, escore e volume fecal de cães adultos em atividade.

“…Quando a densidade energética de um alimento diminui, os animais tendem a aumentar o consumo para que a demanda de energia seja atendida (ROMSOS et al, 1976;ROMSOS et al, 1978). Houve um período de 10 dias antecedentes à data do início do experimento para a adaptação ao manejo, principalmente para que os animais se acostumassem à presença dos novos tratadores.…”

“…Os animais foram alojados individualmente em canis de, aproximadamente, 1,5 m x 3,0 m, com piso de cimento para possibilitar a colheita das amostras (Figura 12) (AAFCO, 1999;MALAFAIA et al, 2002;AHLSTROM & SKREDE, 1998;KENDALL et al, 1981;LILIENTHAL et al, 2002;ROMSOS et al, 1978e MURRAY et al, 1998. Vale ressaltar que houve aleatorização através de sorteio para definir em qual canil cada animal ficaria alojado.…”

“…Para tanto, foi realizada a coleta total das fezes durante a fase de coleta (quatro dias) de cada período, para que sua consistência fosse determinada e desta forma recebesse um escore (BEDNAR et al, 2000;AHLSTROM & SKREDE, 1998;KENDALL et al, 1981;ROMSOS et al, 1978;LILIENTHAL et al, 2002). As fezes da fase de adaptação ao alimento (6 dias) não foram consideradas na elaboração do escore médio final (KENDALL, 1981).…”