Dietary intake and practices in the Hong Kong Chinese population.
OBJECTIVES: To examine dietary intake and practices of the adult Hong Kong Chinese population to provide a basis for future public health recommendations with regard to prevention of certain chronic diseases such as cardiovascular disease, hypertension, and osteoporosis. PARTICIPANTS: Age and sex stratified random sample of the Hong Kong Chinese population aged 25 to 74 years (500 men, 510 women). METHOD: A food frequency method over a one week period was used for nutrient quantification, and a separate questionnaire was used for assessment of dietary habits. Information was obtained by interview. RESULTS: Men had higher intakes of energy and higher nutrient density of vitamin D, monounsaturated fatty acids and cholesterol, but lower nutrient density of protein, many vitamins, calcium, iron, copper, and polyunsaturated fatty acids. There was an age related decrease in energy intake and other nutrients except for vitamin C, sodium, potassium, and percentage of total calorie from carbohydrate, which all increased with age. Approximately 50% of the population had a cholesterol intake of < or = 300 mg; 60% had a fat intake < or = 30% of total energy; and 85% had a percentage of energy from saturated fats < or = 10%; criteria considered desirable for cardiovascular health. Seventy eight per cent of the population had sodium intake values in the range shown to be associated with the age related rise in blood pressure with age. Mean calcium intake was lower than the FAO/WHO recommendations. The awareness of the value of wholemeal bread and polyunsaturated fat spreads was lower in this population compared with that in Australia. There was a marked difference in types of cooking oil compared with Singaporeans, the latter using more coconut/palm/mixed vegetable oils. CONCLUSION: Although the current intake pattern for cardiovascular health for fat, saturated fatty acid, and cholesterol fall within the recommended range for over 50% of the population, follow up surveys to monitor the pattern would be needed. Decreasing salt consumption, increasing calcium intake, and increasing the awareness of the health value of fibre may all be beneficial in the context of chronic disease prevention. (+info)
Prior protein intake may affect phenylalanine kinetics measured in healthy adult volunteers consuming 1 g protein. kg-1. d-1.
Study of the amino acid metabolism of vulnerable groups, such as pregnant women, children and patients, is needed. Our existing protocol is preceded by 2 d of adaptation to a low 13C formula diet at a protein intake of 1 g. kg-1. d-1 to minimize variations in breath 13CO2 enrichment and protein metabolism. To expand on our potential study populations, a less invasive protocol needs to be developed. We have already established that a stable background 13CO2 enrichment can be achieved on the study day without prior adaptation to the low 13C formula. Therefore, this study investigates phenylalanine kinetics in response to variations in prior protein intake. Healthy adult subjects were each fed nutritionally adequate mixed diets containing 0.8, 1.4 and 2.0 g protein. kg-1. d-1 for 2 d. On d 3, subjects consumed an amino acid-based formula diet containing the equivalent of 1 g protein. kg-1. d-1 hourly for 10 h and primed hourly oral doses of L-[1-13C]phenylalanine for the final 6 h. Phenylalanine kinetics were calculated from plasma-free phenylalanine enrichment and breath 13CO2 excretion. A significant quadratic response of prior protein intake on phenylalanine flux (P = 0.012) and oxidation (P = 0.009) was identified, such that both variables were lower following adaptation to a protein intake of 1.4 g. kg-1. d-1. We conclude that variations in protein intake, between 0.8 and 2.0 g. kg-1. d-1, prior to the study day may affect amino acid kinetics and; therefore, it is prudent to continue to control protein intake prior to an amino acid kinetics study. (+info)
Thiamine deficiency is prevalent in a selected group of urban Indonesian elderly people.
This cross-sectional study involved 204 elderly individuals (93 males and 111 females). Subjects were randomly recruited using a list on which all 60-75 y-old-people living in seven sub-villages in Jakarta were included. The usual food intake was estimated using semiquantitative food frequency questionnaires. Hemoglobin, plasma retinol, vitamin B-12, red blood cell folate and the percentage stimulation of erythrocyte transketolase (ETK), as an indicator of thiamine status, were analyzed. Median energy intake was below the assessed requirement. More than 75% of the subjects had iron and thiamine intakes of approximately 2/3 of the recommended daily intake, and 20.2% of the study population had folate intake of approximately 2/3 of the recommended daily intake. Intakes of vitamins A and B-12 were adequate. Biochemical assessments demonstrated that 36.6% of the subjects had low thiamine levels (ETK stimulation > 25%). The elderly men tended to have lower thiamine levels than the elderly women. The overall prevalence of anemia was 28.9%, and the elderly women were affected more than the elderly men. Low biochemical status of vitamins A, B-12 and RBC folate was found in 5.4%, 8.8 % and 2.9% of the subjects, respectively. Dietary intakes of thiamine and folate were associated with ETK stimulation and plasma vitamin B-12 concentration (r = 0.176, P = 0.012 and r = 0.77, P = 0.001), respectively. Results of this study suggest that anemia, thiamine and possibly vitamin B-12 deficiency are prevalent in the elderly living in Indonesia. Clearly, micronutrient supplementation may be beneficial for the Indonesian elderly population living in underprivileged areas. (+info)
The sodium concentration of enteral diets does not influence absorption of nutrients but induces intestinal secretion of water in miniature pigs.
Contradictory opinions exist as to whether the sodium concentration of enteral diets influences absorption of macronutrients and transepithelial movement of sodium and water. Therefore, we investigated the effects of various sodium concentrations of enteral diets on absorption of macronutrients and on net fluxes of sodium and water. In unanesthetized miniature pigs, a 150-cm jejunal segment was perfused with an oligopeptide (Peptisorb), an oligomeric and a polymeric diet. The polymeric diet was supplemented with pancreatic enzymes. The sodium concentrations varied between 30 and 150 mmol/L. The energy density was 3.4 MJ/L. The sodium concentration of the diets did not influence absorption of macronutrients and of total energy. However, increasing sodium concentrations of the diets were associated with increasing osmolality of the solutions, resulting in a linear increase in net secretion of water and flow rate of chyme. With all diets and sodium concentrations net secretion of sodium occurred. The sodium secretion was independent of the initial sodium concentration of the diets. It was linearly correlated with net flux of water and was largest in miniature pigs infused with the oligomeric diet. The sodium concentration of the jejunal effluent did not correspond to the initial sodium concentration of the diets. The present results indicate that enteral feeding of diets with high energy density inevitably increases net secretion of water and sodium as sodium concentration increases. Therefore, the sodium concentration of diets should be as low as possible to meet only the minimal daily requirement of sodium. Low sodium concentrations of diets have no negative effects on absorption of macronutrients. (+info)
Descriptive analysis of eating regulation in obese and nonobese children.
Bite rate, sip rate, and concurrent activities of six 7-yr-old children, three obese and three nonobese, were observed at lunchtime over a six-month period. A procedure for decreasing bite rate, putting eating utensils down between bites, was implemented in a multiple-baseline across-subjects design. Sip rates and concurrent activities were observed to assess behavioral covariations. In addition, bite rate and amount of food completed were computed over six food categories to analyze food preferences. Results indicated the control of bite rate acorss all subjects, with a significant reduction in amount of food consumed. Correlations between the response classes indicated they were at least partially independent. Differences in eating behavior of obese and nonobese subjects were observed for breadstuffs and milk drinking. (+info)
Regulation of fatty acid homeostasis in cells: novel role of leptin.
It is proposed that an important function of leptin is to confine the storage of triglycerides (TG) to the adipocytes, while limiting TG storage in nonadipocytes, thus protecting them from lipotoxicity. The fact that TG content in nonadipocytes normally remains within a narrow range, while that of adipocytes varies enormously with food intake, is consistent with a system of TG homeostasis in normal nonadipocytes. The facts that when leptin receptors are dysfunctional, TG content in nonadipocytes such as islets can increase 100-fold, and that constitutively expressed ectopic hyperleptinemia depletes TG, suggest that leptin controls the homeostatic system for intracellular TG. The fact that the function and viability of nonadipocytes is compromised when their TG content rises above or falls below the normal range suggests that normal homeostasis of their intracellular TG is critical for optimal function and to prevent lipoapoptosis. Thus far, lipotoxic diabetes of fa/fa Zucker diabetic fatty rats is the only proven lipodegenerative disease, but the possibility of lipotoxic disease of skeletal and/or cardiac muscle may require investigation, as does the possible influence of the intracellular TG content on autoimmune and neoplastic processes. (+info)
Influences of low intensity exercise on body composition, food intake and aerobic power of sedentary young females.
The present study was designed to investigate the influences of aerobic training on the body composition, aerobic power and food intake of sedentary young females in relation to the initial levels of these variables. Thirty one untrained college females (age = 19.8 +/- 0.2 yr, stature = 154.4 +/- 0.8 cm, body mass = 53.3 +/- 1.2 kg, mean +/- SEM) participated in an exercise regimen consisting of 40% of maximum oxygen uptake (VO2max) for 30 minutes per day on a bicycle ergometer 5 times a week in a training period of 12 weeks. Food consumption was ad libitum but the content of daily food intake was recorded accurately throughout the whole training period and analyzed weekly. The average body mass index (BMI) and fat mass relative to body mass (% FM), estimated from the data of skinfold thickness, decreased significantly after the 12 wk training. There were significant negative correlations between the relative changes (% delta s) and initial levels of both body mass (r = -0.447, p < 0.05) and fat mass (r = -0.638, p < 0.05), but the corresponding correlation for lean body mass (LBM) was not significant (r = 0.186, p > 0.05). While the energy intake during the training period did not differ significantly from that during the control period on the average, the % delta value in energy intake between the two periods was negatively correlated to the energy intake during the control period (r = -0.604, p < 0.05). In addition, there were low but significant negative correlations between both the initial levels of BMI and %FM and % delta in energy intake; r = -0.413 (p < 0.05) for BMI and r = -0.393 (p < 0.05) for %FM. However, no significant correlations were found between % delta in energy intake and those in body composition variables (r = 0.116 to 0.237, p > 0.05). On the average VO2max relative to body mass (VO2max/BM) increased significantly, but VO2max relative to LBM (VO2max/LBM) did not. However, not only VO2max/BM but also VO2max/LBM was negatively correlated to the initial level; r = -0.671 (p < 0.05) for VO2max/BM and r = -0.625 for VO2max/LBM. Thus, the present results indicate that whether the body composition, food intake and aerobic power of sedentary young females can be modified by the exercise regimen eliciting 40% of VO2max depends on their initial levels. (+info)
Evaluation of life-cycle herd efficiency in cow-calf systems of beef production.
A deterministic beef efficiency model (BEM) was used to evaluate life-cycle herd efficiency (LCHE) in cow-calf beef production systems using four breed groups of beef cattle. The breed groups were Beef Synthetic #1 (SY1), Beef Synthetic #2 (SY2), Dairy Synthetic (DS), and purebred Hereford (HE). The LCHE was defined over the lifetime of the herd as the ratio of total output (lean meat equivalent) to total input (feed equivalent). Breed differences in LCHE were predicted with the larger/slower maturing DS being most efficient at each age of herd disposal and reproductive rate. This was mainly because, at any average age at culling, the dams of DS breed group were less mature and so had been carrying relatively lower maintenance loads for shorter periods and positively influencing LCHE. Higher LCHE was predicted with improvement in reproductive performance if there were no associated extra costs. However, this declined markedly if there was a delay in marketing of offspring. As average age at culling increased from 4 to 6 yr, efficiency declined sharply, but it began to recover beyond this age in most breed groups. We concluded that the slower maturing DS breed group may be more efficient on a herd basis in cow-calf systems and that improvements in reproductive rate not associated with extra costs improve life-cycle efficiency. Culling cows soon after their replacements are produced seems efficient. (+info)