Compensatory Increase In Food Intake Research Articles

Defective diurnal changes of food intake, plasma glucose and insulin in rats with a transplantable islet cell tumour.

Subcutaneous implantation of small fragments of a radiation-induced transplantable rat insulinoma into the subscapular region of 16- to 17-week-old male NEDH rats resulted, over a 22-day period, in the progressive development of marked hyperinsulinaemia and severe hypoglycaemia, despite a compensatory increase in food intake. Diurnal changes were examined at 3-hourly intervals for 24 h in control rats and tumour-bearing rats at 20-21 days after transplantation. The control animals exhibited distinct diurnal changes of food intake, glucose and insulin concentrations. Food intake was greatest between 17.00 and 23.00 h; plasma insulin was greatest between 20.00 and 23.00 h, and plasma glucose was raised at 20.00, 02.00 and 05.00 h, compared with the other times. In contrast, insulinoma-bearing rats displayed no diurnal changes other than a small decrease in food intake between 05.00 and 11.00 h. Plasma glucose and insulin concentrations were significantly different from control rats at all times, and food intake was significantly increased between 23.00 and 17.00 h. These observations demonstrate that the transplantable insulinoma not only causes hyperinsulinaemia and hypoglycaemia but results in hyperphagia and defective diurnal changes of food intake, plasma glucose and insulin concentrations. Interruption of nutrient intake by withdrawal of food for 6 h exacerbated the hypoglycaemia of insulinoma-bearing rats leading to coma.

Is a fat metabolite the major diet dependent accelarator of aging?

Previous work with a high fat/low carbohydrate diet indicated that Drosophila melanogaster aged faster on that diet than on a high carbohydrate/low fat diet. This could be due to one of eight possibilities enumerated. Oxygen consumption of flies on the high fat/low carbohydrate diet is initially the same as that on the control diet. Subsequently the oxygen consumption falls to below control levels at older ages. No increased rate of living is indicated. A starvation resistant strain is described. The male eats less food, and yet maintains a body fat level indistinguishable from the parent strain. The lifespan and most physiological indices of aging used indicate that the process of aging is unchanged. Nutrient dilution produces a nearly compensatory increase in food intake with a reduced body fat and body energy reserves. The indices of aging used indicate that the rate of aging is reduced under these circumstances. These results are consistent with the possibility that fat or a fat metabolite alters the rate of aging. It is argued from previous data that body fat itself is not likely to be the important factor, rather a metabolite is probably involved.

Recovery of lipid mass after removal of adipose tissue in ground squirrels.

Male golden-mantled ground squirrels subjected to surgical removal of substantial portions of inguinal, retroperitoneal, and epididymal adipose tissue [lipectomy (Lipx)] or to sham lipectomy (Sham) during the early prehibernatory fattening phase did not differ in body mass 4 mo later at the time of their annual body weight peaks. Body mass restoration by Lipx squirrels was achieved without compensatory increases in food intake. There was little or no regeneration of epididymal adipose tissue, complete regeneration of the retroperitoneal depot, and an increase in mass of subcutaneous fat of Lipx animals. Epididymal and retroperitoneal adipocytes were equivalent in size in Sham and Lipx squirrels; adipocytes in subcutaneous fat were 20% larger in Lipx than in Sham animals. Generation of the annual body mass cycle of this ground squirrel involves active regulation of the lipid mass.

Dietary components and plasma insulin responses to fasting and refeeding in genetically obese hyperglycaemic (ob/ob) mice.

To investigate the role of dietary components in the hyperinsulinaemia of the obese hyperglycaemic (ob/ob) syndrome, plasma insulin responses to fasting and refeeding were examined in Aston ob/ob mice supplied with standard diet, non-digestible-carbohydrate test food, and isoenergetic test foods from which either carbohydrate, protein or fat was omitted. During fasting, plasma insulin concentrations fell more rapidly and to a greater extent than plasma glucose. Refeeding the standard diet raised insulin concentrations above normal, associated with a 25% compensatory increase in food intake over 24 h. Test foods supplied to previously fed or fasted mice produced glucose responses consistent with the available carbohydrate content. Carbohydrate-free food (protein and fat) provided a small insulinotropic stimulus; the effect of protein-free food (carbohydrate and fat) was greater; and the combination of carbohydrate with protein (fat-free food) evoked a marked insulin response. In contrast, insulin concentrations declined in mice given the non-digestible-carbohydrate food. Consumption of the standard diet was increased after 24 h feeding non-digestible-carbohydrate food, but was unaffected by a 30 h fast initiated 54 h previously. These results demonstrate that hyperinsulinaemia in ob/ob mice is not merely triggered by the ingestion of bulk, but depends on the type of nutrient ingested. Dietary carbohydrate appears to be the major stimulus to the hyperinsulinaemia, with an important augmentation in the presence of protein. Since direct glucose stimulation of insulin release is defective in ob/ob mice, the hyperinsulinaemia must be mediated by increased activity of the enteroinsular axis.

The interrelationship between the olfactory bulbs and the basomedial hypothalamus in controlling food intake, obesity and endocrine functions in the chicken

Surgical removal of the olfactory bulbs (OB) in the chicken indicated an increase in thyrotropic activity followed by a compensatory increase in food intake, as shown earlier. Basomedial hypothalamic (BMH) lesions in these birds caused changes in certain parameters which strongly infer hypoactivity of the thyrotropic axis. The lesions also caused development of typical hypothalamic obesity demonstrating both dynamic and static phases. Removal of the OB in BMH lesioned birds in their static phase of obesity, caused no demonstrable physiological changes. While removal of the OB caused an increase in somatotropic activity, the opposite was found in BMH lesioned birds. Those animals in which OB were removed and BMH was destroyed, demonstrated a decrease in somatotropic activity. It is suggested that the syndrome caused by BMH lesions dominates that caused by removal of the OB. The possibility of involvement of the OB in the control of thyrotropic and somatotropic activities mediated by the basomedial hypothalamus, is discussed.

Effect of Exercise Alone on the Weight of Obese Women

Eleven obese women progressively increased periods of walking each day for one year or longer while no dietary restriction was imposed. No weight loss occurred until walking exceeded 30 minutes daily. Generally, weight loss paralleled length of time spent walking. When a certain amount of walking was maintained and weight stabilized at a lower level, more weight loss occurred when walking was increased. Weight loss was slow and proceeded at a rate much less than anticipated if no compensatory increase in food intake had occurred. A marked decrease in skinfold thickness over the upper part of the arm occurred, suggesting that loss of fat accounted for most, if not all, of the weight loss.

Food and water intake and weight regulation in the pigeon

The interaction of eating and drinking and the relation between intake and body weight was examined in pigeons maintained under laboratory conditions in order to obtain normative data on intake and weight regulation in this species. Under ad lib conditions food and water intake values are correlated, while deprivation of either nutrient leads to a reduction in the intake of the other. A linear relation between the log food intake and the log body weight was found under both ad lib and deprivation conditions. Following a period of food deprivation the pigeon shows both a short-term and a long-term compensatory increase in food intake whose magnitude is directly proportional to the degree of body weight loss produced by deprivation. The findings for the pigeon are similar in many respects to those reported for the rat and are discussed in relation to weight regulation and motivational mechanisms in hunger and thirst.

The Role of Homeostasis in Adipose Tissues upon the Regulation of Food Intake of White Leghorn Cockerels

INTRODUCTIONTHE White Leghorn cockerel normally accumulates little fat in its adipose tissues. Presumably the dipose tissues are under homeostatic control which regulates the amount of fat in the adipose tissues. Control over homeostasis in the adipose tissues seems to reside in the hypothalamus since lesions in the ventromedial area of the hypothalamus cause hyperphagia and obesity (Lepkovsky and Yasuda, 1966); the lesions may have acted centrally and evoked urges to eat (appetite); or the lesions acted indirectly and upset homeostasis in the adipose tissues and elicited the accumulation of abnormally large amounts of fat in the depots. The accumulation of fat in the adipose tissues, evoked by the diversion of food energy to the depots, was accompanied by a compensatory increase in food intake. The objective of this study was to secure information on the effect of the forced feeding of excessive amounts of food into White Leghorn cockerels…