Dietary patterns and non-communicable disease risk in Indian adults : secondary analysis of Indian Migration Study data

Acknowledgements The authors thank the IMS study team members and field staff involved in the generation and processing of IMS data. Financial support: This study forms part of the Sustainable and Healthy Diets in India (SAHDI) project supported by the Wellcome Trust ‘Our Planet, Our Health’ programme (grant number 103932). The Wellcome Trust had no role in the design, analysis or writing of this article. The IMS was funded by Wellcome Trust (grant number GR070797MF). L.A.’s PhD studentship is funded by the Leverhulme Centre for Integrative Research on Agriculture and Health (LCIRAH).Peer reviewedPublisher PD

Associations between diet, physical activity and body fat distribution: a cross sectional study in an Indian population.

BACKGROUND: Obesity is a growing health problem in India and worldwide, due to changes in lifestyle. This study aimed to explore the independent associations between dietary and physical activity exposure variables and total body fat and distribution in an Indian setting. METHODS: Individuals who had participated in the Indian Migration Study (IMS) or the Andhra Pradesh Children And Parents' Study (APCAPS), were invited to participate in the Hyderabad DXA Study. Total and abdominal body fat of study participants was measured using DXA scans. Diet and physical activity (PA) levels were measured using questionnaires. RESULTS: Data on 2208 participants was available for analysis; mean age was 49 yrs in IMS, 21 yrs in APCAPS. Total energy intake was positively associated with total body fat in the APCAPS sample: a 100 kcal higher energy intake was associated with 45 g higher body fat (95% CI 22, 68). In the IMS sample no association was found with total energy intake, but there was a positive association with percent protein intake (1% higher proportion of energy from protein associated with 509 g (95% CI 138,880) higher total body fat). Broadly the same pattern of associations was found with proportion of fat in the abdominal region as the outcome. PA was inversely associated with total body fat in both populations (in APCAPS, one MET-hour higher activity was associated with 46 g (95% CI 12, 81) less body fat; in the IMS it was associated with 145 g less body fat (95% CI 73, 218)). An inverse association was observed between PA and percentage abdominal fat in the IMS but no association was seen in the APCAPS population. CONCLUSIONS: In this Indian population, there was an inverse association between PA and body fat. Associations between body fat and dietary variables differed between the younger APCAPS population and older IMS population. Further longitudinal research is needed to elucidate causality and directions of these associations across the life course

The long term impact of cataract surgery on quality of life, activities and poverty: results from a six year longitudinal study in Bangladesh and the Philippines.

BACKGROUND: Cataract surgery has been shown to improve quality of life and household economy in the short term. However, it is unclear whether these benefits are sustained over time. This study aims to assess the six year impact of cataract surgery on health related quality of life (HRQoL), daily activities and economic poverty in Bangladesh and The Philippines. METHODS AND FINDINGS: This was a longitudinal study. At baseline people aged ≥50 years with visual impairment due to cataract ('cases') and age-, sex-matched controls without visual impairment were interviewed about vision specific and generic HRQoL, daily activities and economic indicators (household per capita expenditure, assets and self-rated wealth). Cases were offered free or subsidised cataract surgery. Cases and controls were re-interviewed approximately one and six years later. At baseline across the two countries there were 455 cases and 443 controls. Fifty percent of cases attended for surgery. Response rates at six years were 47% for operated cases and 53% for controls. At baseline cases had poorer health and vision related QoL, were less likely to undertake productive activities, more likely to receive assistance with activities and were poorer compared to controls (p<0.05). One year after surgery there were significant increases in HRQoL, participation and time spent in productive activities and per capita expenditure and reduction in assistance with activities so that the operated cases were similar to controls. These increases were still evident after six years with the exception that time spent on productive activities decreased among both cases and controls. CONCLUSION: Cataract causing visual loss is associated with reduced HRQoL and economic poverty among older adults in low-income countries. Cataract surgery improves the HRQoL of the individual and economy of the household. The findings of this study suggest these benefits are sustained in the long term

Nutritional profile of Indian vegetarian diets--the Indian Migration Study (IMS).

BACKGROUND: The cardiovascular and other health benefits and potential harms of protein and micronutrient deficiency of vegetarian diets continue to be debated. METHODS: Study participants included urban migrants, their rural siblings and urban residents (n = 6555, mean age - 40.9 yrs) of the Indian Migration Study from Lucknow, Nagpur, Hyderabad and Bangalore. Information on diet (validated interviewer-administered semi-quantitative food frequency questionnaire), tobacco, alcohol, physical activity, medical histories, as well as blood pressure, fasting blood and anthropometric measurements were collected. Nutrient databases were used to calculate nutrient content of regional recipes. Vegetarians ate no eggs, fish, poultry and meat. Using multivariate linear regression with robust standard error model, we compared the macro- and micro-nutrient profile of vegetarian and non-vegetarian diets. RESULTS: Vegetarians, (32.8% of the population), consumed greater amounts of legumes, vegetables, roots and tubers, dairy and sugar, while non-vegetarians had a greater intake of cereals, fruits, spices, salt (p < 0.01), fats and oils. Vegetarians had a higher socioeconomic status, and were less likely to smoke, drink alcohol (p < 0.0001) and engage in less physical activity (p = 0.04). On multivariate analysis, vegetarians consumed more carbohydrates (β = 7.0 g/day (95% CI: 9.9 to 4.0), p < 0.0001), vitamin C (β = 8.7 mg/day (95% CI: 4.3 to13.0), p < 0.0001) and folate (β = 8.0 mcg/day (95% CI: 3.3 to 12.7), p = 0.001) and lower levels of fat (β = -1.6 g/day (95% CI: -0.62 to -2.7), p = 0.002), protein (β = -6.4 g/day (95% CI: -5.8 to -7.0), p < 0.0001), vitamin B12 (β = -1.4 mcg/day (95% CI: -1.2 to -1.5), p < 0.0001) and zinc (β = -0.6 mg/day (95% CI: -0.4 to -0.7), p < 0.0001). CONCLUSION: Overall, Indian vegetarian diets were found to be adequate to sustain nutritional demands according to recommended dietary allowances with less fat. Lower vitamin B12 bio-availability remains a concern and requires exploration of acceptable dietary sources for vegetarians

The association between a vegetarian diet and cardiovascular disease (CVD) risk factors in India: the Indian Migration Study.

BACKGROUND: Studies in the West have shown lower cardiovascular disease (CVD) risk among people taking a vegetarian diet, but these findings may be confounded and only a minority selects these diets. We evaluated the association between vegetarian diets (chosen by 35%) and CVD risk factors across four regions of India. METHODS: Study participants included urban migrants, their rural siblings and urban residents, of the Indian Migration Study from Lucknow, Nagpur, Hyderabad and Bangalore (n = 6555, mean age-40.9 yrs). Information on diet (validated interviewer-administered semi-quantitative food frequency questionnaire), tobacco, alcohol, physical history, medical history, as well as blood pressure, fasting blood and anthropometric measurements were collected. Vegetarians ate no eggs, fish, poultry or meat. Using robust standard error multivariate linear regression models, we investigated the association of vegetarian diets with blood cholesterol, low density lipoprotein (LDL), high density lipoprotein (HDL), triglycerides, fasting blood glucose (FBG), systolic (SBP) and diastolic blood pressure (DBP). RESULTS: Vegetarians (32.8% of the study population) did not differ from non-vegetarians with respect to age, use of smokeless tobacco, body mass index, and prevalence of diabetes or hypertension. Vegetarians had a higher standard of living and were less likely to smoke, drink alcohol (p<0.0001) and were less physically active (p = 0.04). In multivariate analysis, vegetarians had lower levels of total cholesterol (β =  -0.1 mmol/L (95% CI: -0.03 to -0.2), p = 0.006), triglycerides (β =  -0.05 mmol/L (95% CI: -0.007 to -0.01), p = 0.02), LDL (β =  -0.06 mmol/L (95% CI: -0.005 to -0.1), p = 0.03) and lower DBP (β =  -0.7 mmHg (95% CI: -1.2 to -0.07), p = 0.02). Vegetarians also had decreases in SBP (β =  -0.9 mmHg (95% CI: -1.9 to 0.08), p = 0.07) and FBG level (β =  -0.07 mmol/L (95% CI: -0.2 to 0.01), p = 0.09) when compared to non-vegetarians. CONCLUSION: We found beneficial association of vegetarian diet with cardiovascular risk factors compared to non-vegetarian diet

Legume consumption and its association with fasting glucose, insulin resistance and type 2 diabetes in the Indian Migration Study.

OBJECTIVE: Legume consumption is associated with lower fasting glucose (FG) and insulin levels in nutrition trials and lower CVD mortality in large-scale epidemiological studies. In India, legumes are widely consumed in various preparations, yet no epidemiological study has evaluated the association of legumes with FG levels, insulin resistance and diabetes risk. The present study aimed to fill this gap. DESIGN: Fasting blood samples, in-person interviews to obtain information on demographic/socio-economic factors, physical activity, alcohol and tobacco use, and anthropometric measurements were collected. Dietary intakes were assessed by an interviewer-administered, validated, semi-quantitative FFQ. SETTING: Lucknow, Nagpur, Hyderabad and Bangalore, India. SUBJECTS: Men and women (n 6367) aged 15-76 years - urban residents, urban migrants and their rural siblings. RESULTS: In multivariate random-effects models adjusted for age, BMI, total energy intake, macronutrients, physical activity and rural/migration status, daily legume consumption was not associated with FG (P-for-trend=0·78), insulin resistance (homeostasis model assessment score; P-for-trend=0·73) or the prevalence of type 2 diabetes mellitus (P-for-trend=0·41). Stratified analyses by vegetarian diet and migration status did not change the findings. Inverse associations between legumes and FG emerged for participants with lower BMI and higher carbohydrate, protein, fat and sugar intakes. CONCLUSIONS: Although legumes are essential in traditional Indian diets, as well as in prudent and Mediterranean diets in the West, we did not find an association between legumes and markers of glycaemic control, insulin resistance or diabetes, except for subgroups based on BMI and macronutrient intake. The ubiquitous presence and complexity of legume preparations in Indian diets may contribute to these findings

Association between empirically derived dietary patterns with blood lipids, fasting blood glucose and blood pressure in adults - the India migration study.

BACKGROUND: Dietary patterns (DPs) in India are heterogenous. To date, data on association of indigenous DPs in India with risk factors of nutrition-related noncommunicable diseases (cardiovascular disease and diabetes), leading causes of premature death and disability, are limited. We aimed to evaluate the associations of empirically-derived DPs with blood lipids, fasting glucose and blood pressure levels in an adult Indian population recruited across four geographical regions of India. METHODS: We used cross-sectional data from the Indian Migration Study (2005-2007). Study participants included urban migrants, their rural siblings and urban residents and their urban siblings from Lucknow, Nagpur, Hyderabad and Bangalore (n = 7067, mean age 40.8 yrs). Information on diet (validated interviewer-administered, 184-item semi-quantitative food frequency questionnaire), tobacco consumption, alcohol intake, physical activity, medical history, as well as anthropometric measurements were collected. Fasting-blood samples were collected for estimation of blood lipids and glucose. Principal component analysis (PCA) was used to identify major DPs based on eigenvalue> 1 and component interpretability. Robust standard error multivariable linear regression models were used to investigate the association of DPs (tertiles) with total cholesterol (TC), low density lipoprotein-cholesterol (LDL-C), high density lipoprotein-cholesterol (HDL-C), triglycerides, fasting-blood glucose (FBG), systolic and diastolic blood pressure (SBP and DBP) levels. RESULTS: Three major DPs were identified: 'cereal-savoury' (cooked grains, rice/rice-based dishes, snacks, condiments, soups, nuts), 'fruit-vegetable-sweets-snacks' (Western cereals, vegetables, fruit, fruit juices, cooked milk products, snacks, sugars, sweets) and 'animal food' (red meat, poultry, fish/seafood, eggs) patterns. High intake of the 'animal food' pattern was positively associated with levels of TC (β = 0.10 mmol/L; 95% CI: 0.02, 0.17 mmol/L; p-trend = 0.013); LDL-C (β = 0.07 mmol/L; 95% CI: 0.004, 0.14 mmol/L; p-trend = 0.041); HDL-C (β = 0.02 mmol/L; 95% CI: 0.004, 0.04 mmol/L; p-trend = 0.016), FBG: (β = 0.09 mmol/L; 95% CI: 0.01, 0.16 mmol/L; p-trend = 0.021) SBP (β = 1.2 mm/Hg; 95% CI: 0.1, 2.3 mm/Hg; p-trend = 0.032); DBP: (β = 0.9 mm/Hg; 95% CI: 0.2, 1.5 mm/Hg; p-trend = 0.013). The 'cereal-savoury' and 'fruit-vegetable-sweets-snacks' patterns showed no association with any parameter except for a positive association with diastolic blood pressure for high intake of 'fruits-vegetables-sweets-snacks' pattern. CONCLUSION: Our results indicate positive associations of the 'animal food' pattern with cardio-metabolic risk factors in India. Further longitudinal assessments of dietary patterns in India are required to validate the findings

Relative contribution of diet and physical activity to increased adiposity among rural to urban migrants in India:A cross-sectional study

BACKGROUND: In common with many other low- and middle-income countries (LMICs), rural to urban migrants in India are at increased risk of obesity, but it is unclear whether this is due to increased energy intake, reduced energy expenditure, or both. Knowing this and the relative contribution of specific dietary and physical activity behaviours to greater adiposity among urban migrants could inform policies for control of the obesity epidemic in India and other urbanising LMICs. In the Indian Migration Study, we previously found that urban migrants had greater prevalence of obesity and diabetes compared with their nonmigrant rural-dwelling siblings. In this study, we investigated the relative contribution of energy intake and expenditure and specific diet and activity behaviours to greater adiposity among urban migrants in India. METHODS AND FINDINGS: The Indian Migration Study was conducted between 2005 and 2007. Factory workers and their spouses from four cities in north, central, and south of India, together with their rural-dwelling siblings, were surveyed. Self-reported data on diet and physical activity was collected using validated questionnaires, and adiposity was estimated from thickness of skinfolds. The association of differences in dietary intake, physical activity, and adiposity between siblings was examined using multivariable linear regression. Data on 2,464 participants (median age 43 years) comprised of 1,232 sibling pairs (urban migrant and their rural-dwelling sibling) of the same sex (31% female) were analysed. Compared with the rural siblings, urban migrants had 18% greater adiposity, 12% (360 calories/day) more energy intake, and 18% (11 kilojoules/kg/day) less energy expenditure (P < 0.001 for all). Energy intake and expenditure were independently associated with increased adiposity of urban siblings, accounting for 4% and 6.5% of adiposity difference between siblings, respectively. Difference in dietary fat/oil (10 g/day), time spent engaged in moderate or vigorous activity (69 minutes/day), and watching television (30 minutes/day) were associated with difference in adiposity between siblings, but no clear association was observed for intake of fruits and vegetables, sugary foods and sweets, cereals, animal and dairy products, and sedentary time. The limitations of this study include a cross-sectional design, systematic differences in premigration characteristics of migrants and nonmigrants, low response rate, and measurement error in estimating diet and activity from questionnaires. CONCLUSIONS: We found that increased energy intake and reduced energy expenditure contributed equally to greater adiposity among urban migrants in India. Policies aimed at controlling the rising prevalence of obesity in India and potentially other urbanising LMICs need to be multicomponent, target both energy intake and expenditure, and focus particularly on behaviours such as dietary fat/oil intake, time spent on watching television, and time spent engaged in moderate or vigorous intensity physical activity

Association Between Urban Life-Years and Cardiometabolic Risk: The Indian Migration Study

Urban living is associated with an increase in cardiometabolic risks, but the speed at which these risks are accrued over time is unknown. Using a cross-sectional sibling-pair design, the authors surveyed migrant factory workers and their spouses from 4 cities in India together with their rural-dwelling siblings and examined the associations between urban life-years and cardiometabolic risk factors. Data on 4,221 participants (39% women; mean age = 41 years) were available (2005–2007). In regression models, a 2-slope pattern for body fat (with a marked shift at 10 years) was found, whereas a common slope could be accepted for other risk factors. In men, the regression coefficients (per decade of urban life) were 2.5% in the first decade and 0.1% thereafter for body fat; 1.4 mm Hg for systolic blood pressure; and 7% for fasting insulin. Age, gender, marital status, household structure, and occupation did not influence the patterns appreciably; however, stronger gradients for adiposity were noted in migrants from lower socioeconomic positions. The findings suggest that body fat increases rapidly when one first moves to an urban environment, whereas other cardiometabolic risk factors evolve gradually. Public health interventions focused on the control of obesity in newer migrants to urban areas, particularly those from lower socioeconomic positions, may be beneficial