Background
Nutrition is an important factor in health and disease [
1]. The nutrition transition is marked by a shift away from relatively monotonous diets of varying nutritional quality toward an industrialized diet that is usually more varied, includes more preprocessed food, more food of animal origin, more added sugar and fat, and often more alcohol. This is accompanied by shift in the structure of occupations and leisure toward reduced physical activity [
2].
The pattern of nutritional disorders in the developing world is further complicated by sociological changes which are taking place due to urbanization and changing lifestyles [
3,
4]. In five out of the six regions of WHO deaths caused by chronic diseases dominate the mortality statistics [
5,
6]. Although infectious diseases, still predominate in sub-Saharan Africa and will do so for the foreseeable future, 79% of all deaths worldwide that are attributable to chronic diseases are already occurring in developing countries [
5,
6].
Epidemiological studies show that nutritional inadequacy can influence the incidence and the severity of infectious diseases [
7‐
10]. In Ethiopia, nutritional problems and infectious diseases are amongst the major health problems [
8]. Chronic health disorders such as obesity, diabetes and cardiovascular diseases (CVDs) have been increasing in the country since the last few decades [
9]. According to the Ethiopian nationwide study on income, expenditure and consumption of 2005, fruits accounted for the lowest proportion (0.2%) of the per capita expenditure as compared to cereals (20.4%), pulses (3.9%), oils and fats (2%), khat (1.4%), or alcohol and tobacco (1.1%). A strong association between nutritional impairment and the development of chronic diseases such as cardiovascular diseases, cancer, and diabetes has been reported. Population-based data on cause of death from a few isolated studies, in predominantly rural populations, in Ethiopia demonstrate that a considerable proportion of the disease burden in these populations is due to CVD and other chronic diseases [
11].
However, there is paucity of data on dietary intakes and nutritional status in Northwest Ethiopia. Therefore, this study was aimed to evaluate the dietary intake and anthropometric variables of urban residents in Northwest Ethiopia [
12].
Methods
Study area and subjects
This cross-sectional study was conducted in Gondar city, Northwest Ethiopia in July 2005. Gondar is a zonal capital city located 750kms north of Addis Ababa in Amhara Region. The city has a longitude and latitude of 12°36′N 37°28′E. Based on figures from the Ethiopian Central Statistical Agency in 2005, Gondar has an estimated total population of 194,773 of whom 97,625 were males and 97,148 were females. Sample size was calculated based on expected estimates of 50% of BMI < 18.5, 95% confidence limits, and a 5% marginal error, the required sample was 384. Probability sampling in a form of simple random and two-stage probability sampling method was used for selecting the required size. The first stage of the sampling was started by selecting kebeles (smallest administrative unit) using simple random sampling. At the second stage, a random sample of households was selected based on a sampling frame from the 1994 census and adapted for recent population changes.
Out of 384 participants, data of 28(7%) of the study participants were incomplete and excluded of the statistical analysis. Nutritional status and dietary intake indicators was primary variables of interest. In addition, a structured questionnaire was used to collect information on socio-demographic variables including sex, age, religion, marital status, occupation, educational status and monthly family income. Monthly family income was estimated by combining incomes reported for husband, wife, son and/or daughter. The inclusion criteria for participation were age >18 year, not acutely ill at the time of survey and not diagnosed for chronic illnesses. Ethical approval for this study was obtained from the Research Ethics Committee of the University of Gondar. Informed consent was obtained from all subjects.
Anthropometric and body composition measurements
Body weight (kg) was measured using an electronic scale to the nearest 10 g, and standing height was measured using a wall stadiometer to the nearest 0.1 cm. Subjects were instructed to take off their shoes before performing these measurements. Body Mass Index (BMI) was calculated as body weight (kg)/height (m
2). The classifications of BMI applied in this study were recommended by the World Health Organization (WHO) [
13] BMI values of <18.5 kg/m
2 and >25 kg/m
2 represented thinness and overweight, respectively. An acceptable weight was considered to fall within these two extremes. Waist and hip circumferences were measured with a flexible steel metric tape at the nearest 0.5 cm. Central obesity was also calculated and defined on the basis of WHR. The cut-off value of central obesity was considered high risk WHR= >0.80 or waist measurement >80% of hip measurement for women for females and >0.95 for males that is >95% for men indicates central (upper body) obesity and is considered high risk for diabetes & CVS disorders. A WHR below these cut-off levels is considered low risk [
13].
Interview using food frequency questionnaire
Data were collected by face-to-face interview using a structured Food Frequency Questionnaire (FFQ) modified from the Helen Keller International FFQ that was used previously in Ethiopia, to estimate meat and vegetable consumption that was in addition to the staple food intake [
14]. The FFQ included eight food categories (Meat, Egg, Fish, Fat rich food, Vegetables, Fruits, Diary products, Sweet food) and was designed to obtain qualitative information about the usual food consumption patterns with an aim to assess the frequency with which certain food items or groups are consumed during a specific time period [
15]. All frequency variables were coded as never or hardly ever, once a month, 2–3 times a month, once a week, 2–3 times a week, 4–6 times a week, and at least once a day.
24-h dietary recall
The respondents were asked to recall the exact food intake of the previous day. Detailed descriptions of all foods including recipes and beverages consumed were recorded. Quantities of food consumed were estimated in household measures. One single 24-h recall was collected for every participant. Only one adult individual was selected from a house hold. For the transformation of household measurements and centimetres into grams, the portion sizes were weighed with a digital household dietary scale (Omron Electronic kitchen scale, Omron, Tokyo, Japan). Information from the 24-h protocols was entered and analyzed with Microsoft EXCEL software. The various food items mentioned in the recall were transformed into their corresponding weight of raw food ingredients. Ethiopian food composition tables [
16] or food composition table for use in Africa [
17], for those not available in the former, was used to calculate energy and nutrients content. Major nutrients in the food composition tables were measured. The data were subsequently converted into the amount of energy and nutrient intake per individual per day. Relative validity of 24-h recall was determined by comparison data obtained from the same participants using a food-frequency questionnaire. Furthermore, three 24-h recalls were repeated in 10% of the sample. The dietary results are under preparation.
Adequacy of the macronutrients and micronutrients intake was evaluated according to the Dietary Reference Intakes (DRI) of The Institute of Medicine of The National Academies [
18]. The reported energy intakes were compared with estimated minimal energy requirements to assess adequacy. Basal Metabolic Rate (BMR) was estimated using the sex and age specific equations of FAO/WHO/UNU expert consultations. The BMR was then multiplied by a factor which stands for physical activity level for each individual [
19].
Dietary quality
As a measure of overall nutrient adequacy, mean adequacy ratio (MAR) was calculated as the mean of the nutrient adequacy ratios (NARs) for the intake of energy and nine nutrients (protein, calcium, iron, phosphorus, retinol, thiamin, riboflavin, niacin, ascorbic acid), each truncated at 1 so that a nutrient with a high NAR could not compensate for a nutrient with a low NAR [
20].
Statistical analysis
The mean ± SD daily nutrient intake was computed and tabulated. The mean intakes of energy, macronutrients and micronutrients were compared between men and women by independent sample t-test. Chi square test of proportion was used to determine the percentage of participants with intakes at or below the recommended daily allowance and adequate intakes. Correlation test was tested to examine the relationship between socioeconomic factors on dietary intake and selected nutritional variables. All statistical analyses were undertaken using SPSS version 13. P values less than 0.05 were considered statistically significant.
Discussion
This cross-sectional study provides data on the nutritional status and dietary intake of urban residents in Gondar city, Northwest Ethiopia. The results of this study indicate that the diets of urban residents included in this study are undesirable according to the Dietary Reference Intakes (DRIs) used. Overall, participant diets included too much energy-dense food and saturated fat and inadequate intakes of micronutrients. The men seem to have more than adequate intake compared to women. Irrespective of sex, micronutrient intake is very low in the area. BMI data point out the prevalence of a high percentage of overweight and obese subjects in both sexes.
The results also showed that males had a greater mean in BMI and Waist-to-Hip Ratio (WHR) than females, related to physiological differences between male and females [
22,
23]. Higher BMI and WHR may be considered as indicators of high risk factors for cardiovascular disease since they have strong relation to lipid profile in both sex groups [
22,
24‐
26]. A considerable proportion of urban residents (21.3%) in Gondar had overweight and obesity in contrast to previous reports of low prevalence of overweight in Ethiopia [
27]. Increased dietary energy and fat intake, coupled with insufficient physical activity, is implicated in the rapidly growing prevalence of overweight and obesity in sub Saharan Africa, where there is a longstanding tradition favoring obesity over thinness. Overweight in general, and abdominal obesity in men, is regarded as a sign of health and wealth in many communities in Africa, including Ethiopia. Thinness, in contrast, is considered as a sign of illness or poverty [
25,
26].
Although, there is limited data on the BMI distribution or prevalence of overweight and obesity in sub Saharan African countries, in other African countries, the prevalence of obesity was consistently higher in urban areas [
24,
25].
Although, eating more vegetables and fruits as the part of Dietary Approaches to Stop Hypertension (DASH) diet are associated with reduced risk for cardiovascular diseases [
28] In Gondar and most cities in the country, people are reluctant to consume vegetables especially in commercial food catering places and in social occasions where food is served to large number of guests. There is widespread fear of infection, particularly with amoeba, from consuming uncooked vegetables. It is common to see that a large part of the vegetables cultivated in cities are contaminated with water that is contaminated with sewerage and use of infected manure as a fertilizer.
Fruits are not also part of the regular daily diet in Ethiopia. Unlike other populations where fruits follow meals for dessert, instead tea and coffee are the predominant accessories to meals in this population. Fruits are more commonly consumed during weekends, social occasions or holidays. They are the preferred gift while visiting sick people (patients) at home or in health facilities. The price of common fruits, such as oranges and bananas, has remained generally low for many years in Ethiopia until a recent surge, which was partly attributed to increasing exports. In addition, according to results of this study, consumption of fish is very small due to cultural aversion to eating fish although one of the biggest lakes (Lake Tana) is only 60 km from Gondar.
Intake of fat by the study participants was higher than the suggested acceptable macronutrient distribution range which is a negative impact of nutrition transition [
29‐
31]. The dietary changes of the nutrition transition involve large increases in the consumption of fat (especially saturated fat) and sugar, marked increases in animal products, and a decline in unrefined cereal and, thus, in fiber intakes [
32,
33]. It is recommended that fiber intake could be improved by taking whole grain than refined grain intake; thus, nutrition education programs are needed to improve the dietary intake and for healthy eating pattern [
34]. As in many sub-Saharan Africa countries, in Ethiopia, an increased level of body fat is associated with beauty, prosperity, health, and prestige, despite its negative impact on health. Thinness, in contrast, is perceived to be a sign of ill health or poverty and is something to be feared and avoided, particularly in recent years, when it has been associated with AIDS [
26,
35].
Micronutrients are required for virtually all metabolic and developmental processes. The large percentage of study subjects with inadequate intakes of calcium, retinol, thiamin, riboflavin, niacin and ascorbic acid indicates that micronutrient deficiencies are still major public health problems in developing countries [
36‐
38]. These dietary pattern changes in which the macronutrient pattern could already be associated with an increased risk of overweight, obesity and other non communicable diseases [
39,
40] while the improvements in micronutrient intakes in urban subjects, did not reach recommended values for some micronutrients [
34,
41]. It is conceivable that in many overweight and obese subjects, sub-optimal micronutrient intakes could lead to a “double burden” of co-existence of under- and over-nutrition in the same person. It is further conceivable that some of the observed micronutrient deficiencies, such as those with anti-oxidant properties, could contribute to the increased risk of non communicable diseases in these subjects.
Our data agree with previous studies in different countries suggesting lower intakes of essential nutrients, vitamins, and minerals, especially calcium, thiamin and niacin in developing countries during nutrition transition [
42‐
44]. It is understandable that with economic development, people will choose to follow a more palatable diet than traditional diets high in fiber and low in fat. But it is more difficult to understand why adult Africans, often from poor, food-insecure households, are so vulnerable to obesity when they experience the nutrition transition. It has been suggested that based on the Barker hypothesis [
45] of fetal programming for vulnerability to non communicable diseases in later life when the expectant mother is nutritionally compromised, stunted children and adults born from these mothers in African households are more vulnerable to obesity when they are suddenly following a modern, “Western” diet [
46].
This study has also shown that the major determinants for frequency of food consumption among adults are socioeconomic. The more income the family generates, the better their frequency of food consumption and hence BMI. Although not statistically significant, level of education is negatively correlated with frequency of consumption for oil and butter. Health education campaigns warning against butter as source of saturated fatty acids and recommending unsaturated fats might have influenced the behaviors of the highly educated in the study area. Nutrition education of the masses needs to be intensified to encourage a healthy lifestyle. Food fortification programmes to include micronutrients are also advocated.
The limitations of this study include single 24 h dietary recall, thereby providing a less precise measure of intake. The study did not include the rural communities due to financial constraint. Yet, the representativeness of the urban population samples to the corresponding strata in the whole country is limited due to possibly marked diversity in socioeconomic and cultural background of different populations in the country. Additionally, the cross-sectional nature of our study ruled out a determination of the role of poor diet in the development of high-risk anthropometric measures or the role of lack of knowledge of nutrition in making poor dietary habit.
Competing interests
The authors declare that they have no competing interests.
Authors' contributions
AK, BA, MA, AM, BM, FM and BF were all involved in the design of the study, carrying out the data collection, and drafting the manuscript. All authors read and approved the final manuscript.