Nutritional influences over the life course on lean body mass of individuals in developing countries

Summary of review¹

Location: Global

What we know: The double burden of undernutrition and overnutrition is a concern in societies in transition.

What this article adds: The high fat, low lean body mass (LBM) composition of South Asians is associated with elevated risk of chronic disease.  A review concludes it is likely due to both developmental programming in early life, and nutrition and lack of exercise through childhood and adolescence. Food diversification with inclusion of animal-source foods would help reduce childhood undernutrition and increase adult LBM. Childhood undernutrition and adult overnutrition are a continuum rather than mutually exclusive problems. A larger body of evidence is needed to inform policy.

Nutrition transition in developing and middle-income countries has led to a rapid increase in non-communicable diseases, including type 2 diabetes mellitus, hypertension, dyslipidaemia and cardiovascular disease, all known to be associated with obesity. The prevalence of obesity assessed with a body mass index (BMI) criterion, however, is still low in these settings, despite rapid gains observed in recent years. In contrast, undernutrition, especially childhood undernutrition, is highly prevalent and remains a pressing issue. In addition, studies from China, Brazil, Mexico and Russia have reported the coexistence of undernutrition in children and overnutrition in adults living in the same household. The double burden of undernutrition and obesity-related chronic diseases has been highlighted as a key concern in societies in transition. 

A number of studies have assessed the ethnic differences in body composition highlighting the peculiar high fat, low muscle mass composition of South Asians compared with other ethnic groups. This particular body composition characteristic is considered an important determinant of the elevated risk of metabolic syndrome in this population. Evidence suggests that this fat phenotype in relatively thin individuals may be programmed by undernutrition in early life, as ethnic differences in body composition are evident even at birth. A large number of studies (mainly observational studies in humans and animal experiments) conducted during the past two decades have indicated that compromised nutrition and growth during early life may be associated with subsequent lower lean body mass (LBM), adiposity, and metabolic syndrome. 

Early nutritional influences, however, cannot completely account for the low LBM in some population groups, and it is well recognised that nutritional influences operating during later life have a cumulative impact on LBM in adulthood.  A large body of evidence suggests that nutritional and exercise interventions help to improve LBM throughout the life course. A recent review examined the possible nutritional influences on adult LBM using a life-course approach which emphasises the influences affecting health and disease in adulthood that operate during different life stages cumulatively and interactively.  The life-course approach proposes two theoretical models in which exposures may affect the risk of disease: a ‘critical period’ or ‘developmental programming’ model and an ‘accumulation of risks’ model based on the effects of long-term gradual insults. Two lines of evidence were reviewed: the role of early nutrition in developmental programming of LBM, and the role of nutritional influences that affect LBM throughout the life course. 

The reviewers conclude that examining the evidence using this life-course approach suggests that nutrition influences LBM through developmental programming in early life, as well as through its continued role in the accretion of LBM during childhood and adolescent growth. Suboptimal LBM associated with nutritional deficits at different life stages may predispose individuals to fat accretion by influencing the energy balance. Nutrients such as proteins, zinc, calcium and vitamin D are particularly important for linear growth during childhood as well as for improvement of muscle mass in later life. Diversification of cereal-based diets in developing countries by the inclusion of animal-source foods would help reduce childhood undernutrition and increase adult LBM, thereby mitigating the double burden of malnutrition in transitioning communities. 

The authors conclude that understanding childhood undernutrition and adult overnutrition as a continuum rather than mutually exclusive problems is particularly useful in formulating nutrition policies to address both these challenges. However, a larger base of evidence is needed to support necessary policy changes. In particular, more studies are necessary to evaluate the efficacy and effectiveness of strategies to improve birth weight and linear growth in children and to promote optimal body composition with higher LBM in adults in developing countries. In addition, studies on the feasibility and cost-effectiveness of these approaches in different settings are required, since the effectiveness of these interventions is likely to be context specific.

¹ Kulkarni B, Hills A and Byrne N (2014). Nutritional influences over the life course on lean body mass of individuals in developing countries. Nutrition Reviews, Vol 72 (3), pp 190-204. Doi:101111/nure.12097