Sri Lankan adults had relatively low dietary diversity values, in particularly, relatively higher FVS and DDS and lower DDSP value indicates that although people consume several type of food items, the amount of consumption is low for many food groups. In WHO STEP Survey reported that 3% of Sri Lankan consume more than five fruits and vegetable per day . Rathnayake et al. reported much lower mean DDS (4.4) and FVS (8.4) among group of rural elderly people . DDS, DDSP and FVS values for Indian Tamils were remarkably less than Sinhalese and Muslim ethnic groups. It is reported that malnutrition and nutritional deficiencies are highest in the estate sector where most of Indian Tamils are living . Although we have lack of data on nutrient adequacy in this study sample, it can be postulate that low dietary diversity may causes deficiencies among Sri Lankan adults. People with better education may have high profile occupations and greater purchasing power could lead for higher consumption of different food variety. Although no previous data available on dietary diversity among Sri Lankan adults, children who lived in estate sector had a lower dietary diversity . Moreover, lower maternal education was negatively associated with receiving a diverse diet for those children . Obese and abdominal obese participants had higher DDS, DDSP and FVS values compared to non-obese and non-abdominally obese groups.
Sri Lankans consume excess amount of starchy foods but per below amount of fruits, vegetables and dairy products . Table 2 and 3 showed that 100% values for starch group in every DDS and DDSP indicating starchy staple food is the inclusive food group in Sri Lankan meals. Nearly five percent participants had almost starch meal without significant amount of other food groups for whole day, this is due to some people consume cereal (e.g. rice) with a starchy vegetable (e.g. potato curry). Predominantly carbohydrate diets raise plasma glucose, insulin, triglycérides and non-esterified fatty acids leading to insulin resistance . Total carbohydrate intake is associated with risk of diabetes among South Indian adults . High prevalence of diabetes and its complications among Sri Lankan adults may be associated with starch based but poor variety meals [18, 27]. Amongst the food groups of dietary pyramid, meat, green leafy vegetables, milk and fruits were least frequent. Increased intake of fruits and vegetables could play a protective role against obesity associated metabolic risk factors in South Indians who is prone to get premature coronary artery disease . Reasons for monotonous diet among Sri Lankan adults needed to be explored although it is associated with low obesity level. Public Health initiatives to improve appropriate diversity of diet are important.
Torheim et al. reported a positive correlation between energy intake and DDS, as well as variety of different food groups in Mali . When a diet is composed of foods that differ on sensory characteristics such as color flavor and shape may cause hyperphagia . Animal and human studies showed that food intake increases when there is more variety in a meal or diet and that greater dietary variety is associated with increased body weight and subsequently obesity . Dietary variety within food groups was positively associated with body fatness among healthy adults . Several studies showed a positive correlation between calorie intake and dietary diversity [17, 29]. On the contrary, an inverse association between DDS and obesity/abdominal adiposity was reported among the female students of Isfahan University . In US women, low BMI was associated with higher DDS; in US men, there was no clear relation of BMI to dietary diversity . Our result shows that positive association between all three dietary diversity indices with calorie intake suggesting that consumption of large number of food items may lead to excessive intake of calorie and weight gain. Although many dietary guidelines promote consumption of varied diet, it should be selective (e.g. vegetables) rather than absolute number. Moreover, Food Guide pyramids are not designed to maintain energy balance, but show nutritional adequacy and balance . Increased dietary diversity in health promotion may not be appropriate for combating obesity epidemic in Sri Lankan. A reduction in dietary variety of highly palatable and energy rich foods may be an appropriate strategy to prevent and treat obesity in Sri Lankan. In the same time, to prevent deficiencies foods with high nutrient but low calories (e.g. green vegetables, low fat milk) should be encouraged.
We used a single 24 hour recall to obtain usual intake, however multiple dietary recalls during weekdays and weekends may provide a better picture of the habitual diet. In the nutritional literature, DDS and FVS are widely used and showed appropriate correlation with nutritional status and association with chronic disease. Simple counting of food groups or consumed food items are used for define diet diversity scores. These methods have limitations. First, although it is not easy to distinguish healthy and unhealthy food items, these counting systems are assigned equal values for every food item respective of the health outcome (e.g. fruits and sweets). Second, the distributions of individual food quantities are not considered by count measures. In this exercise we defined DDSP with consumption of minimum of one portion of respective food groups; however we did not define an upper limit. Drescher et al. recommend considering, health values of a consumed food items for measure healthy food diversity . Another limitation is that we did not measure the diversity within food groups and most of Sri Lankan dishes are mixed in nature, which causes considerable practical limitations for food item groupings. Furthermore, there is no an updated food composition tables for Sri Lankan mixed dishes in particularly for micronutrients. Therefore we were not able to calculate nutrient adequacy ratio and mean adequacy ratio. Moreover, lack of physical activity data among this population limit us to calculate daily energy requirements. Although the main aim of this study is to explore the associations between dietary diversity/variety and obesity.
A follow up study showed an inverse dietary diversity-mortality association was adjusted for potential dietary and socio-demographic confounders . DDS is population specific and there is no standard scoring method, therefore it is invariably difficult to compare DDS values among different countries. Because of cross sectional nature of this study, we cannot express long term health outcome with regards to dietary diversity among Sri Lankan adults. Moreover, obesity is associated with multiple socio-economical factors which could be possible confounding factors for diet diversity. Prospective studies are needed to explore association between dietary diversity and weight gain/obesity.
Acknowledging the limitations of this study, these results showed the dietary diversity, portions consumption and number of food item intakes according to different socio-demographic characteristics. Globally, normative data on ‘ideal’ or ‘target’ levels of diversity are usually not available. Therefore, our results can be used to assess current picture of the dietary diversity among Sri Lankan adults. Repeating similar study in a given time may help to assess improvements in food security and expected changes in the population. Illangasekara et al. reported temporal trends in the prevalence of diabetes mellitus in a rural community in Sri Lanka which is closely accompanied by an increase in the monthly income. But there is a lack of data on changes in dietary habits in this population with related to epidemic of diabetes and other diet associated metabolic disorders. Although our aim was to assess the individual diet diversity, as our sample included predominantly housewives and in Sri Lanka majority of people consume homemade foods. These results can be used as household dietary diversity values. Therefore, these values may indicate socio-economic level of the household .