HOMEOSTASIS BE MAINTAINED ON A VEGETARIAN DIET

Homeostasis be maintained on a Vegetarian Diet

Homeostasis be maintained on a Vegetarian Diet

Introduction

Vegetable foods are associated with many metabolic functions in nutrition at all stages of development. They reduce calorie and protein density, modulate the absorption of nutrients and antigens, and promote the formation of feces. Dietary fiber (especially from green leafy vegetables, but also from legumes and whole cereals) and the antinutrients often bound to them can mediate these effects. (Hegsted , Schuette , Zemel , 2001) As far as weaning schedules are concerned, the metabolic effects of vegetable foods are of prime importance for infant physiology.

The presence of animal proteins during and at the end of the weaning period were found by recent Italian surveys to create a widespread protein imbalance, especially with the use of whole cow milk or protein-rich follow-up formulas. Supplementing vegetable foods before meat is introduced into the diet may be advisable to prevent upsetting the infant's metabolic homeostasis. The baseline energy expenditure seems to be set higher for formula-fed infants than for those who are breast-fed, and this in turn triggers a higher energy demand. The metabolic response of artificially fed infants is to increase insulin release to regulate the different rates of energy intake, storage, and expenditure. Hypertrophy of the liver and kidney may result, in an attempt to maintain homeostasis in the fuel metabolism. (Hegsted , Schuette , Zemel , 2001)

Water-soluble fiber plays a particular role in the absorption of macronutrients by increasing the viscosity of the gastrointestinal contents. This delays immediate enzymatic action on substrates and prolongs the delivery of absorbable nutrients to the mucosal cells. The antinutrients mentioned before are also involved in this process, although to a varying extent. (Hegsted , Schuette , Zemel , 2001)

The relationship between fiber supply and watery diarrhea in early childhood has been investigated by Brown et al, who found a positive effect of a soybean polysaccharide on the severity and duration of diarrhea symptoms. A direct link between compliance with a recommended diet of 150 g/d green leafy vegetables and a decrease in immunoglobulin E (IgE) values with the improvement of the symptoms were also found among a population of children with cronic diarrhea in their second year of life. Other investigators recently observed the reversal of colonic fluid secretion induced by enteral feeding among healthy adult volunteers by means of the direct infusion into the colon of mixtures of short-chain fatty acids. Thus, the effects of fiber on the duration of diarrheal disorders cannot be viewed as simply "cosmetic," because such effects seem to be mediated through complex biochemical and cellular mechanisms. (Hegsted , Schuette , Zemel , 2001)

Reducing calorie density with an increased consumption of tiber foods not only restores the balance between energy supply and demand but also seems to afford protection to the colon mucosa against immunogenic agents, either directly or by induced modifications of the composition of the colonic flora. Children with phenylketonuria (PKU) on a low-phenylalanine diet because of the ...