Nutrition transition and chronic diseases in Nigeria.

Nutrition transition goes with industrialisation that fosters human development which is usually desirable, especially in developing nations. However, the health consequences of this development include high rates of preventable non-communicable diseases which are usually undermined in the quest for industrialisation. The goal of the present paper is to provide evidence-based information that will promote healthy lifestyle including healthy consumption pattern among urban dwellers. Relevant local and international literature was accessed and reviewed to harvest evidence-based information through the use of validated review guide in addition to observation from the field experience. Industrialisation promotes creation of more job opportunities and this facilitates proliferation of fast-food eateries in the cities. However, it was also observed that many of the available workplaces in urban areas are not health-promoting because employees have poor access to preventive health information and sensitisation to healthy lifestyle has been poorly considered. Ironically, weight gain among urban workers which may be linked with increased intake of high-energy foods and low participation in physical activities as a result of accessibility to many energy saving devices have been highlighted as some of the pull-pull factors that attract many people to the cities. Using the concept of health promoting workplace, the workforce in urban areas can be trained as agent of change in health-promoting lifestyle. Consumption of healthy indigenous foods through aggressive promotion of its health potentials should be seriously advocated through the use of existing structure of urban fast-food vendors who constitute a strong stakeholder in nutrition transition.

Nutrition education in medical training: the need to reconsider the sacrosanctity of medical education in Nigeria.

The "no controversy" status of the important role of nutrition in maintaining good health and disease management is becoming a gold standard in medical practice. Medical schools in developed countries and some in developing countries are beginning to renew interest in nutrition education for medical professionals. Despite difficulties envisaged in modifying the medical school curricula, it is inevitable that medical professionals need some basic nutrition knowledge appropriate for medical counselling in disease prevention and management. Cost effectiveness in providing health care services is now an important policy tool, which emphasizes preventive medical care. This is dependent on good nutrition education, which informs not only on food but healthcare and good environment. This article examines the need for nutrition education in medical schools, approaches that can be used to introduce nutrition education, using the available information from medical schools that have already integrated nutrition into their medical education curricula. It also identifies some of the barriers and strategies to overcome including specific actions for nutrition educators or whoever may be saddled with the responsibilities for initiating the development of nutrition curriculum for medical education.

Protein requirement of young adult Nigerian females on habitual Nigerian diet at the usual level of energy intake.

A short-term N balance study was conducted in twelve healthy female adults aged 21-32 years to determine their protein requirement. Four dietary protein levels (0.3, 0.4, 0.5 and 0.6 g protein/kg per d) were used. Energy intake of the subjects was kept constant at 0.18 MJ/kg per d. All subjects maintained their normal activity throughout the study period. N excretion was determined from the measurements of N in a total collection of urine, faeces, sweat and menstrual fluid for each dietary period. N balance during the four protein levels were -15.15 (SD 5.95), -5.53 (SD 6.71), +6.15 (SD 4.76) and +12.05 (SD 8.63) mg N/kg per d for 0.3, 0.4, 0.5 and 0.6 g protein/kg per d respectively. The calculated average N requirements from regression analysis was 76.0 (SD 3.37) mg N/kg per d (0.48 g protein/kg per d). The estimate of allowance for individual variation to cover the 97.5% population was 95 mg N/kg per d (0.6 g protein/kg per d). The net protein utilization (NPU) of the diet was 0.55. When compared with a similar study with men, there was a significant difference in the protein requirement between sexes. Thus, the unjustifiable sex difference in the protein allowance recommended by the Food and Agriculture Organization/World Health Organization/United Nations University (1985) Expert Consultation group must be reviewed.

A metabolic nitrogen balance study for 40 d and evaluation of the menstrual cycle on protein requirement in young Nigerian women.

A long-term N balance study was carried out to determine the adequacy of an estimated protein requirement level recommended for young healthy Nigerian women and the effect of the menstrual cycle on the requirement. Eleven healthy young women, 25 (SD 2.6) years, were fed on a diet providing 0.6 g protein (N x 6.25)/kg per d and an average energy intake of 0.17 (SD 0.012) MJ/kg per d. Urine, faeces, sweat and menstrual fluids were collected for estimation of N balance. Menstrual N loss varied among individuals ranging from 46 to 124 mg N/d with an average of 89 (SD 21.8) mg N/d. Individual N balance was found to vary according to the day of the menstrual cycle. Positive N balances were recorded at about ovulation while negative balances were observed just before the onset of menstruation. The average N balance ranged from +8.49 (SD 5.64) to -430 (SD 7.84) mg N/kg per d. Nevertheless, an overall cumulative positive N balance of +5.7 (SD 6.98) mg N/kg per d which did not change significantly with time was observed for the last 5 d of two consecutive 20 d diet periods, although three subjects were in negative N balance. Blood biochemical measurements were stable except for one subject who had elevated serum aspartate aminotransferase (EC 2.6.1.1) levels. These findings suggest that our estimate of protein requirements was sufficient to achieve N balance equilibrium in a majority (70%) of young women. However, to satisfy 97.5% of the population, slight adjustments might be necessary in the energy intake since subjects who were in cumulative negative N balance also lost weight.

Nutrient intakes of children in a rural Nigerian community.

The nutrient intakes of 30 children in a rural Nigerian community were assessed by measuring their food intakes for four consecutive days by direct weighing method. The contents of the following six nutrients were calculated: energy, protein, calcium, iron, riboflavin, and vitamin C. The mean (SD) daily energy intakes for the various ages groups were: 1-5 years 801 (317) kcal; 6-10 years 1123 (214) kcal; and 11-15 years 903 (134) kcal, while the mean (SD) daily protein intakes for the same group of children were 21 (11) g; 35 (10) g, and 27 (7) g. These figures show a wide departure from the FAO/WHO/UNU reference values and a worsening of the nutritional status of rural Nigerian children.

Nitrogen balance study in young Nigerian adult males using four levels of protein intake.

1. The present study was carried out to estimate precisely, via the nitrogen balance technique, the protein requirement of Nigerians (earlier estimated via the obligatory N method) using graded levels of protein intake. 2. Fifteen medical students of the University of Ibadan who volunteered to participate in the study were given graded levels of protein (0.3, 0.45, 0.6 and 0.75 g/kg body-weight per d) derived from foods similar to those usually consumed by the subjects. 3. Each subject was given each of the dietary protein levels for a period of 10 d. Subjects were divided into two groups and the feeding pattern followed a criss-cross design with one group starting with the highest level of protein intake (0.3 g). Mean energy intake during each of the eleven experimental periods was maintained at 0.2 MJ/kg per d. After an initial 5 d adaptation period in each experimental period, 24 h urine and faecal samples were collected in marked containers for five consecutive days for N determination. 4. Mean N balance during consumption of the four protein levels (0.30, 0.45, 0.6 and 0.75 g/kg) were -11.02 (SD 8.07), -9.90 (SD 6.64), +9.70 (SD 4.15) and +5.13 (SD 4.62) respectively. Using regression analysis, the mean daily N requirement was estimated at 110.25 mg N/kg body-weight (0.69 g protein/kg body-weight). Estimates of allowances for individual variations to cover 97.5% of the population adjusted this value to 0.75 g protein/kg body-weight. Net protein utilization for the diet at maintenance level was estimated at 57.5.

Long-term evaluation of the adequacy of habitual diets to provide protein needs of adult Nigerian men.

1. A continuous 40 d metabolic nitrogen balance study was conducted on twelve young men aged 25 (SD 2.6) years to evaluate the adequacy of a previously determined safe level of protein intake. 2. Subjects were fed on diets which they were habitually accustomed to and which provided a protein level of 0.75 g protein (N x 6.25)/kg body-weight per d as the safe level and an energy intake level of 0.2 MJ/kg body-weight per d. N balances, including an estimate for integumental losses as well as certain biochemical variables, were determined for the last 5 d of two consecutive 20 d diet periods. 3. Only two of the twelve subjects were observed to be in negative N balance the final 5 d of the 40 d period. N balance was generally positive at 8.24 (SD 8.61) mg N/kg body-weight, thus confirming the adequacy of 0.75 g protein/kg body-weight per d as a safe level of protein intake in the majority of the subjects.

Human protein requirements: obligatory urinary and faecal nitrogen losses and the factorial estimation of protein needs of Nigerian male adults.

1. The present study was designed to use the factorial approach to estimate protein requirements of Nigerian male adults by measuring obligatory nitrogen losses via urine, faeces and sweat when N intake was very low and energy intake adequate. 2. Eight adult men from Osegere village near Ibadan and seven medical students from the University of Ibadan, who volunteered to participate as subjects in the study, were given a low-protein diet (based on staple foods habitually consumed by subjects) for 10 d. Mean daily total protein intake was 4.68 g while that of energy was 0.2 MJ/kg body-weight. After an initial 5 d adaptation period, 24 h urine and faces were collected in marked containers for five consecutive days for N determination. N losses from the skin were also determined in the village adults. 3. Mean daily urinary, faecal and sweat N losses (mg N/kg body-weight) were 45.88 (SD4.84), 21.79 (SD4.19), and 7.46 (SD1.71) from the village adults. The corresponding urinary and faecal N losses from the university students were 43.45 (SD2.28) and 18.32 (SD4.66) (sweat N loss not measured). Thus the total daily obligatory N losses (per kg body-weight) from the village adults and university students were 75.13 and 69.23 mg N respectively (assuming a sweat N loss of 7.46 mg for the university students). After adjusting for requirement and making a 30% allowance for individual variability, the safe level of protein intake was calculated to be 0.78 and 0.73 g protein/kg body-weight for the village men and university students respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Zinc, copper and iron concentrations in the plasma and diets of lactating Nigerian women.

Zinc, copper, iron, protein and energy intakes of 232 lactating women (consuming self-selected diets during the first 3 months post-partum) were computed from food intake values obtained using a 3 d dietary-recall method. Non-pregnant, non-lactating women (100) served as controls. Blood samples of subjects were also analysed for packed cell volume and haemoglobin concentrations as well as for plasma Zn, Cu and Fe levels by atomic absorption spectrophotometry. Except for Fe, intakes of all nutrients measured were significantly lower than recommended dietary allowances for lactation. Daily mean (and SD) Zn, Cu, Fe (mg), protein (g) and energy (MJ) intakes for lactating women were 8.2 (1.6), 1.6 (0.5), 29.0 (5.8), 52.4 (9.2) and 10.21 respectively. There was a significant intercorrelation between the different nutrients in the diet. Mean (and SD) plasma Zn, Cu and Fe concentrations (micrograms/l) during the first 3 months of lactation were 666.0 (76.0), 1290.0 (150.0) and 730.0 (185) respectively. These values were significantly (P less than 0.05) lower in the case of Zn and Fe and higher in the case of Cu than those of non-pregnant, non-lactating women. Maternal plasma levels of the trace elements also varied significantly with nutritional status as indexed by haemoglobin status. Correlation analysis between dietary and plasma trace element concentrations was significant for Zn (r 0.26, P less than 0.0001) and Fe (r 0.17, P less than 0.05). Dietary protein intake was significantly correlated with plasma Zn (r 0.18, P less than 0.005) and Fe (r 0.12, P less than 0.05). While maternal weight, arm circumference and skinfold thickness measurements tended to decrease with increase in the period of lactation, growth performance of entirely breast-fed babies was satisfactory as at the 12th week post-partum.

Relationship between dietary and plasma copper levels of pregnant Nigerian women.

Dietary copper intake as well as plasma copper levels were assessed in a group of pregnant Nigerian women during the third trimester of pregnancy. Intake of zinc, protein and energy was also measured. Dietary intake was assessed by cumulative 24-hour recalls while plasma copper was assessed by atomic absorption spectrophotometry. Dietary copper levels were relatively lower than those documented in the literature for other physiological groups. The intake of other nutrients was below recommended dietary allowances. When corrected for the effect of gestation and maternal age, one-way analysis of variance showed that plasma copper varied with the level of dietary copper intake. Correlation analysis seems to suggest that the influence of dietary copper on plasma levels during pregnancy is partially dependent on the relative amounts of copper and zinc as represented by the copper:zinc ratio in the diets consumed.

Effect of a moderate variation in dietary energy intake on the retention and excretion of zinc, calcium, and magnesium.

Mineral balance was studied by metabolic balance techniques in 13 healthy college females aged 21-23 yr. They were fed diet containing 1780 kcal, 2580 kcal, and 25 g protein in a 20-d experiment period. Both diets contained approximately 5.28 mg zinc, 216.85 mg calcium, and 364.3 mg magnesium. The diet consisted of habitually consumed foods. Blood, urine and fecal samples were collected for mineral analysis using atomic absorption spectrophotometry. Plasma mineral levels were not affected by the change in dietary energy intake. Fecal calcium and magnesium were significantly higher when subjects were fed the low calorie (1780 kcal) diet, whereas there was no significant difference in fecal zinc for the two levels of dietary energy. Urinary calcium and magnesium were also significantly higher when the diet provided 1780 kcal though, on the other hand, urinary zinc was significantly higher when the diet provided 2680 kcal (P<0.05). Urinary calcium and magnesium correlated negatively, whereas urinary zinc correlated positively, with the dietary energy intake (P (o)<0.05). Dietary energy intake has a significant effect on the mineral balance of the subjects.

Calcium, magnesium, and zinc status of young adult females on an adequate protein and calorie intake.

Calcium, magnesium, and zinc balances were determined in eleven young adult college females (mean age, 24.9±2.35) during a 39-d metabolic study when the subjects were fed an adequate calorie and protein diet based on habitually consumed foods. Analysis showed that the dietary contribution of calcium, magnesium, and zinc to the RDA were 53.6, 26.4, and 57.9%, respectively. Mean fecal losses of calcium and magnesium were low, while fecal zinc losses were higher than the daily intake. Mean urinary excretion of calcium was within the normal range, but was low for magnesium whereas urinary zinc was higher than normal. Mean daily apparent retentions of calcium and magnesium were positive, whereas positive apparent retention for zinc were observed in four of the subjects. Plasma calcium and magnesium remained normal, but mean plasma zinc declined at the end of the study. Significant correlations were observed between the fecal losses of calcium and magnesium and calcium and zinc. Urinary calcium also correlated significantly (P<0.05) with urinary magnesium, but not with zinc. It appears that adequate protein and calorie intake in the presence of low dietary intake of calcium, magnesium, and zinc has no significant effect on calcium and magnesium status whereas a lowering effect on plasma zinc and apparent zinc retention was observed in the subjects studied.

Mineral content of colostrum and mature milk of lactating Nigerian women as influenced by stage of lactation.

380 milk samples (96 colostrum and 284 mature milk samples) collected from 240 lactating Nigerian women within the first 9 months of lactation were analyzed for zinc, copper, iron, calcium, and magnesium concentrations by atomic absorption spectrophotometry. Mean levels of zinc, copper, iron, calcium, and magnesium in colostrum were 5.83, 0.52, 0.55, 400, and 33 mcg/ml, respectively; the levels for the same minerals in mature milk collected in the 8th and 12th week of lactation were 3.08, 0.29, 0.38, 300, and 31 mcg/ml, respectively. While milk levels of all minerals decreased with increase in lactation age, zinc levels showed the fastest rate of decrease. Milk zinc levels at the 9th month were only 13% of that in colostrum. Similar percentages for copper, iron, calcium, and magnesium were 49, 60, 34, and 74%, respectively. Estimates of intake by solely breastfed infants during the first 6 months showed gross inadequacies when compared with Recommended Daily Allowances. Results suggest the need for early supplementation, especially as zinc deficiencies as well as a high incicdence of iron deficiency anemia has been reported in Nigerian infants.

Plasma transport proteins in rehabilitated protein-energy malnourished children in Nigeria.

Blood levels of prealbumin, retinol-binding protein, ceruloplasmin and transferrin were monitored during the rehabilitation of thirty protein-energy malnourished children. The children aged between six and fifty-four months were rehabilitated on an out-patient basis and fed locally prepared good quality food while the mothers were given nutrition education coupled with health education. The initial mean anthropometric values and plasma transport protein levels were significantly lower in these children when compared with values obtained from 10 apparently healthy children presenting with no signs or symptoms suggestive of any form of malnutrition. At the end of the rehabilitation period, there was no significant difference in plasma transport protein levels between the previously malnourished children and the normal controls although the malnourished children still demonstrated significant weight deficit.

Plasma zinc status of protein energy malnourished children.

The plasma zinc status, albumin level and alkaline phosphatase activity of 44 protein energy malnourished Nigerian children were compared with those of 10 normal children. Results were classified according to the type and degree of malnutrition. Plasma zinc levels were low in the malnourished groups and tended to vary with the degree of malnutrition as indicated by the level of growth retardation. Levels in the 'normal' group of children suggest a possible presence of marginal zinc nutrition among Nigerian children.

Trace element content of breastmilk from mothers of preterm infants in Nigeria.

Copper, zinc and iron contents were determined in samples of breastmilk obtained from 15 women who gave birth preterm and 20 women who delivered at term. Copper levels in mothers of preterm babies fell from 0.54 microgram/ml in colostrum to 0.30 microgram/ml at the eighth week of lactation while the levels of mothers of term babies fell from 0.34 to 0.27 microgram/ml. Zinc levels fell from 7.14 to 5.36 microgram/ml and from 5.98 to 3.93 microgram/ml. respectively. Iron levels fell from 1.05 to 0.70 microgram/ml and from 0.56 to 0.43 microgram/ml. It appears that breastmilk from mothers giving birth to preterm babies contains significantly higher levels of copper, zinc and iron during the early lactation period when compared to mothers of term babies.

Relationship of zinc and copper concentrations in maternal and cord blood and birth weight.

Twenty and 30 Nigerian women who delivered infants weighing 1500 gm-2500 gm and more than 2500 gm, respectively, were studied. Cord and maternal blood samples collected at delivery were analyzed by atomic absorption spectrophotometry for zinc and copper content. The mean plasma zinc in maternal and cord blood was significantly lower and the mean plasma copper was significantly higher in the low-birth-weight group than in the control group. The zinc level in cord blood was higher than that in maternal blood in both groups. However, the copper level in both groups was lower in cord than in maternal blood.