A heretical view of the American Heart Association's nutritional dogma [abstract]

The dogma is as follows: no more than 33 percent of the calories in the diet should come from fat, and of those no more than 33 percent should come from saturated fat. Because of the saturated fats in eggs and butter, both of these foods are unsuitable. Diets that do not conform to these standards raise serum cholesterol levels and thereby promote coronary heart disease (CHD). However, serum cholesterol is not correlated with dietary cholestorol. diet or drug regimes that reduce serum cholesterol do not reduce mortality. Blood lipoprotein a, the best single predictor of CHD, correlates not at all with fat in the diet but inversely with ascorbic acid. Low-fat diets do not protect against CHD type 2. In practice, they are almost always high-carbohydrate, and often high-sucrose diets. Such diets promote obesity, Type-2 diabetes mellitus, and the production of advanced glycosylation end-products, which in turn promote hypertension and CHD. Because of the need for essential fatty acids, all diets should include unsaturated fatty acids. However, as quantities rise above optimum the unsaturated acids promote greater free radical damage and require increasing amounts of oil-soluble anti-oxidants to counteract this effect. Eggs are excellent food, containing, in addition to protein, carbohydrate, fat and all the vitamins, minerals and essential fatty acids needed to produce a chicken. They do not promot CHD. Nutritionally, butter is much better than margarine which contains large amounts of trans fatty acids, that interfere with the metabolism of essential fatty acids, raise low density lipoprotein and triglycerides and lower high density lipoprotein. The best is a low-carbohydrate diet with little sucrose and adequate levels of vitamins, minerals and essential fatty acids. (AU)

Nutrition and athletic performance

Optimal athletic performance requires adequate nutritional support. This mean getting enough food to meet increased energy needs and a wide variety to ensure adequate nutrient intake. The main energy source should be carbohydrate. Dietary guidelines for healthy eating apply to athletes and diabetics alike. This study evaluated the diets of young athletes for nutritional adequacy and determined the effect on their performance. Sample selection was based on convenience and included normal and diabetic athletes, mainly swimmers and footballers. Attitudes and practices were determined by questionnaire and a 24-hour recall provided data on nutrient intake. BMI and body fat were calculated. Results showed that the nutritional factor most likely to be low was energy. in many cases, this correlated with the athlete's perception of performance. Vitamin and mineral intakes were generally adequate but fibre intake tended to be low. This may be related to the sparsity of fruits and vegetables for many. The main sources of carbohydrate were refined cereals and sugars. Carbohydrate intake ranged from 50-60 percent of calories. Fat intake was relatively high and protein substantial. Most had BMIs above average, with a few underweight and two marginally overweight. Performance was related to quality of diet and importance placed on nutrition. Also critical was the level of training and self-esteem score.(AU)

The effect of the level of dietary protein, carbohydrate and fat on urea kinetics in young children during rapid catch-up weight gain

The kinetics of urea metabolism were measured in children recovering from severe malnutrition. For a period of up to 10 d they receive one of four diets which provided 711 kj (170 kcal)/kg per d. Two groups received a diet with a high protein:energy (P:E) ratio of 10.6 percent (HP), enriched with either fat (HP/F) or maize starch and sucrose HP/C). Two groups received a diet with a low P:E ratio of 8.8 percent (LP), enriched with either fat (LP/F) or maize starch and sucrose (LP/C). The rate of weight gain on the HP diets was significsntly greater than on the LP diets. There was no difference in urea production between any of the four diets: HP/F 1.23 (se 0.12), HP/C 1.37 (se 0.14), LP/F 1.64 (se 0.22) LP/C 1.15 (se 0.15) mmol nitrogen/kg per h. On the HP diets urea excretion was 0.77 (se0.07) mmol N/kg per h, 61 percent of production. There was significantly less urea excreted in the urine on diet LP/C than on LP/F (0.36 (se0.05) and 0.64 (se 0.04)mmol N/kg per h respectively). A significantly greater percentage of the urea production was hydrolysed on the LP diets (61 percent) compared with the HP diets (39 percent), with the consequence that 50 percent of urea-N produced was available for synthetic activity on the LP diets compared with 30 percent on the HP diets. The increase in the urea hydrolysed on the LP diets was equivalent in magnitude to the decreased intake of N, so that overall intake plus hydrolysis did not differ between the LP and HP diets. Crude N balance was similiar on diets HP/F, HP/C and LP/C, but was significantly reduced on diet LP/F. These results show that there is an accommodation in urea kinetics during rapid catch-up weight gain, which becomes evident when the P:E ratio of 8.8 percent, protein is limiting for catch-up growth. When the intake has a P:E ratio of 8.8 percent the pattern of urea kinetics can be modified by the relative proportion of fat and carbohydrate in the diet. The measurement of urea kinetics provides a useful approach to the definition of the adequacy of the protein in the diet. (AU)

A carbohydrate-rich diet not only leads to incorporation of medium-chain fatty acids (6:0-14:0) in milk triglycerides but also in each milk-phospholipid subclass

We isolated phospholipid (PL) subclasses from milk of women in Dominica and Belize. Fatty acid (FA) compositions of PLs and total lipids were determined. In the total-lipid fraction Dominican milk showed higher relative amounts of medium-chain saturated fatty acids (MC-SAFAs; 6:0-14:0) and 22:6n-3 and lower amounts of long-chain saturated fatty acids (LC-SAFAs) and monounsaturated fatty acids (MUFAs). There was a positive relationship between the MC-SAFA content in total lipids and total PLs. Incorporation of MC-SAFAs in PLs occurred at the expense of LC-SAFAs, MUFAs, polyunsaturated fatty acids (PUFAs), and long-chain PUFAs with o20 carbon atoms (LC-PUFAs oC20). Previous studies from western countries revealed low amounts of MC-SAFAs and high amounts of PUFAs and LC-PUFAs oC20 in milk PLs. Our data show that carbohydrate-rich diets give rise to incorporation of MC-SAFAs in PLs at the expense of PUFAs and LC-PUFAs oC20. The data are discussed in relation to the presumed origin of fat-globule membrane phospholipids. (AU)

Glycaemic response to local staple foods in diabetics - abstract

This paper reports the results of a pilot study done to investigate the glycaemic response (glycaemic index or G.I.) of fifteen (15) Type II Barbadian diabetics to different test foods. Subjects were fed four test meals of white bread, white rice, split peas and rice and split peas alone. Each meal contained 50gm of carbohydrate. Using white bread as the standard, Glycaemic Indices (G.I) were determined for each food from blood glucose measurements done over a three-hour period following the meal. Glycosylate haemoglobin (HbAlc) levels were measured as a monitor of diabetic control and were found to correlate well with the fasting blood sugar. White rice is shown to have a very high Glycaemic Index, more than four times that of split peas (102 compared to 24). A mixture of split peas and white rice, in a ration of 1:3, produces a significant decrease in G.I. (15.1+6.3, p < 0.05), although the change varied widely. Well-controlled diabetics (with the lowest HbAlc levels) all had a consistent decrease in G. I. on the food combination 28, (p<0.001), whereas poorly-controlled diabetics showed a small but unexpected increase in the G. I. mean 12.7, (p<0.02). There is an inverse relationship between change in G. I. and HbAlc levels, i.e. the better the diabetic control the greater the "split pea effect". In view of the high use of white rice in the Caribbean, there is an urgent need to dermine glycaemic indices of as many common cheap foods being eaten in the Caribbean as possible, and to ensure that these reference values are available to all those involved in diabetic care (AU)

The effect of the duration of malnutrition on erythrocyte insulin binding and carbohydrate tolerance in rats - abstract

To further investigate the effect of malnutrition on carbohydrate metabolism, we have examined the binding of insulin to its receptor in a rat model. The erythrocytes of malnourished animals bound less insulin than controls (6.4 percent vs 17 percent respectively, p<0.01, at 10 days post-weaning, pw). In the later stages of malnutrition (20 days pw), insulin-binding was significantly less than in the early stage (5 days pw) 2.7 percent vs 14.7 percent, p<0.01 respectively). The decreased in binding was also due to decreased receptor affinity in the malnourished compared to the control (0.54 Ke x 10(to 8 power)/M vs 1.4 Ke x 10(to 8 power/M, p<0.01, at 10 days pw). There was no significant difference between the number ob receptors in malnourished and control states. The malnourished animals became insulin-resistant, with a diminished glucose tolerance and a lowered insulin to glucose ratio. Insulin release was also presumably impaired as the malnourished animals had a lowered plasma insulin concentration compared to the controls of the same age (8 æU/ml vs 15.3 æU/ml, p0.05; 10 days pw). In the control animals, the plasma insulin levels increased with age from 8.1 æU/ml at weaning to 27.5 æU/ml (p<0.05): while increase in plasma insulin values shown by the malnourished was not statistically different (10.34æU/ml, 20 days pw). There was an inverse relationship between plasma insulin levels and insulin-binding as the control animals increased in age. The extent and the duration of manutrition adversely affects the binding of insulin to its receptor. This would contributed to the glucose intolerance characteristic of malnurtition (AU)

A supplementary feeding programme for the management of severe and moderate malnutrition outside hospital

Eighty-seven children with moderate and severe malnutrition were treated by means of a supplementary feeding programme in Trinidad. The programme resulted in an average weight increase similar to that obtained by other authors in Nutrition Rehabilitation Centres and Supervised Supplementary Feeding Programmes elsewhere, over a similar period of time. The weight increase, however, is slow when translated into improvement of reference weight for age. Close supervision resulted in a somewhat faster rate of improvement but increase excessively the cost of rehabilitation. Supervision and education of the mothers carried out by Community Aides did not result in continued improvement after discontinuation of the supplement. However, there was a significant improvement in the quality of the diet given to the supervised children four months after the food supplement and supervision had been discontinued. (Summary)

Nutritional considerations concerning in the staple foods of the English-speaking Caribbean

The staple foods of importance to the English-speaking Caribbean are wheat, starchy fruits, roots and tubers, and to some extent sugar. Their nutritional implications and their contributions to the diet are discussed. Cereals provide more energy and protein per unit weight as purchased than do other staple foods. They also provide important proportions of total average dietary energy and protein. Wheat, the major cereal, is wholly imported and price rises over the past few years have strained national economies. The feasibility of local production of staple foods is discussed. Cereal/legume rotations provide greater energy and protein yields per acre per year than do starchy fruit or root crops under present varietal and agronomic conditions. Retail cost nutrient values for energy and protein are greater for cereals than for starchy fruits, roots and tubers. The conclusion is drawn that, to overcome malnutrition and to keep pace with population growth, more dietary energy needs to become available to the region without reduction in dietary quality. Questions are asked as to the feasibility of rational; import substitutions and improved local yields providing both cheap food to the consumers and good returns to the farmers. (AU)

Observations on the origin of liver fat in infantile malnutrition

Liver samples were obtained by biopsy from malnourished children in Jamaica, and also from a group of children who had recovered from malnutrition. The activity of glucose-6-phosphatase was significantly reduced in the liver of the malnourished children. The ability of liver homogenates to synthesize fat from acetate was less in the malnourished children than in the recovered group, but the difference was not significant. In the malnourished children, the fasting levels of nonesterified fatty acids (NEFA) and glycerol in the plasma were increased. The origin of the excess liver fat in kwashiorkor is discussed, and it is concluded that it is derived directly from dietary carbohydrate (Summary)