Biomedical subjects

I Marques-Lopes

Publications and source records attributed to I Marques-Lopes.

6 recordsLinked to original sources

PubMed2002

[Causes of obesity].

The aetiology and treatment of obesity requires a knowledge of the mechanisms that control the homeostasis of the fuel substrates and adiposity. The processes of regulation adjust the supply of macronutrients and energy demands with the aim of maintaining a stable body mass. In the light of the most recent research, the hypothesis can be advanced that the control of body weight and its composition depends on an axis integrated by three self-regulated components: appetite, stores thermogenesis and fat deposits. The most important factors involved in obesity seem to be dietary habits diet and physical activity, which are affected by genes, which in their turn affect energy expenditure, the metabolism of energy substrates and food consumption. However, the growing rates of obesity cannot be explained exclusively by genetic causes, since they are in some cases associated with the consumption of diets with a high energy density or rich in fat, and by a growing sedentary life style in society, both in developed and developing countries. The study of genetics and life style involved in the increase of body weight and obesity can facilitate the implementation of preventive actions.

English Abstract↗

PubMed2002

[Nervous system and obesity].

In spite of the great daily variations in the ingestion of nutrients, the energy reserves of the body remain constant over time, which suggests the existence of numerous mechanisms regulating adiposity, energy expenditure and appetite. Gastric distention, the intestinal absorption of nutrients, lipid and glycogen reserves, the rate of utilisation of energy substrates on a central and peripheral scale, the palatability of the food and other psychological factors, influence the short term regulation of oxidation and the storage of macronutrients, as well as appetite. Besides, hormones such as insulin and leptin act over the longer term on the brain, reducing ingestion and increasing energy expenditure. Important neuronal circuits regulate this organ, above all at the hypothalamic level, which initiate effector signals that control energy homeostasis. This paper studies the role of the central nervous system in the regulation of appetite and energy balance

English Abstract↗

PubMed2002

[Slimming diets].

Dietetic intervention has the following aims: to achieve a negative energy balance, obtain a healthy weight in the obese person and achieve the installation of healthy eating habits in order to maintain weight loss in the long term. Considering dietetic treatment of obesity as a process that is maintained for long periods of time, dietetic intervention should be carried out depending on the physio-pathological and psycho-social characteristics of the obese person. Besides, dietetic therapy should be balanced, healthy and adapted to the eating preferences of the patient. Over the years, due to need and the quest for rapid weight loss, magic diets have been occasioned, created and invented that have become popular and that lack proven efficacy and scientific rigour. This paper makes reference to a balanced hypocaloric diet and reviews the slimming diets that are best known and most used by the obese and/or overweight population.

English Abstract↗

PubMed2001

Postprandial de novo lipogenesis and metabolic changes induced by a high-carbohydrate, low-fat meal in lean and overweight men.

BACKGROUND: Adjustments of carbohydrate intake and oxidation occur in both normal-weight and overweight individuals. Nevertheless, the contribution of carbohydrates to the accumulation of fat through either reduction of fat oxidation or stimulation of fat synthesis in obesity remains poorly investigated. OBJECTIVE: The objective of this study was to assess the postprandial metabolic changes and the fractional hepatic de novo lipogenesis (DNL) induced by a high-carbohydrate, low-fat meal in lean and overweight young men. DESIGN: A high-carbohydrate, low-fat meal was administered to 6 lean and 7 overweight men after a 17.5-h fast. During the fasting and postprandial periods, energy expenditure (EE), macronutrient oxidation, diet-induced thermogenesis, and serum insulin, glucose, triacylglycerol, and fatty acids were measured. To determine DNL, [1-13C]sodium acetate was infused and the mass isotopomer distribution analysis method was applied. RESULTS: After intake of the high-carbohydrate meal, the overweight men had hyperinsulinemia and higher fatty acid and triacylglycerol concentrations than did the lean men. The overweight group showed a greater EE, whereas there was no significant difference in carbohydrate oxidation between the groups. Nevertheless, the overweight men had a marginally higher protein oxidation and a lower lipid oxidation than did the lean men. DNL was significantly higher before and after meal intake in the overweight men and was positively associated with fasting serum glucose and insulin concentrations. Furthermore, postprandial DNL was positively correlated with body fat mass, EE, and triacylglycerol. CONCLUSION: After a high-carbohydrate, low-fat meal, overweight men had a lower fat oxidation and a higher fractional hepatic fat synthesis than did lean men.

Adult↗

PubMedDate not supplied

[Effects of a dietary intervention on the nutritional status of hemodialyzed patients: differences between men and women].

The growing interest in the nutritional status of dialyzed patients arises from the fact that it plays an important role in the evolution, morbidity and mortality of renal patients. In the current study the effects have been assessed of a dietary intervention lasting 6 months, based on a food exchange list, on the nutritional status of a group of 49 hemodialysis patients as well as the different effects between men and women. The initial and final evaluation of the nutritional status was performed by estimating energy and nutrient intake with a 24 hour recall, determination of body composition by anthropometry, bioelectrical impedance and infrared interactance and biochemical measurements related to the nutritional status of the patients undergoing hemodialysis. At the end of the study, a significant increase was seen in the energy and macronutrient intake, which was more prominent in females. The body composition analysis showed a favourable evolution as compared to other studies; which was better in women who maintained the muscle mass stable and increased fat mass. The biochemical profile showed an increase of the C3 complement, while other markers such as amino acid profile and IGF I remained unchanged at the end of the study, being both similar in males and females. The dietary intervention was found to be useful in the prevention of the progression of malnutrition in these patients, apparently with a more beneficial effect on females.

English Abstract↗

PubMedDate not supplied

[Nutrition and dietary recommendations for the elderly "Public Health" Working Group of the Spanish Nutrition Society].

With the increase of life expectancy, the desire to maintain good health, functionality and maximum quality of life at advanced ages, for which nutrition plays a critical role, is a priority for the elderly. Though genetic factors are a determinant of life expectancy, there are several extrinsic factors which have a great influence on the quality of life of the elderly. Diet and nutritional status have a great influence, especially in the prevention and treatment of several diseases, which affect this heterogeneous and vulnerable age group. The nutritional status and needs of elderly people are associated with age-related biological, psychological and often socio-economic changes. All of these changes can increase the risk of developing a number of age-related diseases. In developed countries the elderly are the most affected by malnutrition, either because of a deficiency (energy and several nutrients) or an excess, leading to obesity and related diseases. This review highlights the most important factors affecting nutritional status in elderly people and focus on the need to maintain adequate physical activity level and an optimal physic, psychic and social functional capacity. It discusses dietary reference intakes and guidelines to improve and/or maintain adequate nutritional status in older people in order to reduce susceptibility to some illness and disease.

Aged↗