Promote Height Growth, Not Weight Gain, in Emerging Countries

March 27, 2013

New data from 5 low- and middle-income countries show that patterns already observed in the Western world are starting to be seen elsewhere: namely, that putting on too much weight in relation to height in middle and late childhood can increase the risk for chronic diseases, such as diabetes, in later life.

Linda S. Adair, PhD, from the department of nutrition, University of North Carolina, Chapel Hill, and colleagues report their findings — from Brazil, Guatemala, India, the Philippines, and South Africa — in the Lancet, published online March 28, 2013.

"We found that if you get heavier during middle and late childhood, that is associated very clearly with an increased risk of type 2 diabetes in adulthood," second author Caroline H.D. Fall , MBChB, from the University of Southampton, United Kingdom, told Medscape Medical News. The findings are important, she said, because "a lot of feeding programs in such countries are aimed at older children, and this is a danger period."

A better approach, the results reveal, is to focus on improved nutrition in the first few years of life. "Weight gain earlier, in infancy, was not associated with any increased risk [of chronic disease later]. If you promote growth in very early life, within the first 1000 days [from conception to age 2 years], that is going to be good for the child, good for survival, giving some protection from adult chronic disease and better educational attainment," Dr. Fall explained.

Also key, the research shows, are efforts to promote height growth, and more work is needed to find ways to improve upon this, she added.

"The very clear message from this study and what has gone before is that gaining weight inappropriately in excess of your height in later childhood is bad, and we should stop doing this," Dr. Fall told Medscape Medical News. Rapid weight gain should not be promoted after the age of 2 or 3 years in children who are underweight but not wasted, and growth monitoring programs should incorporate length and height measures, not just weight measures, she added.

Dr. Fall noted that the new data mirror what has been seen for some time in the West. "It's absolutely identical. This emphasizes what has come out of cohort studies in Europe, the US, and the UK. But obesity in children is still not being take seriously here, and I don't think you can ram this home too often," she commented.

Lessons for Low- and Middle-Income Countries

In an accompanying comment, Zulfiqar A. Bhutta, MD, from Aga Khan University, Karachi, Pakistan, said the findings of Adair and colleagues "are some of the most important from existing cohorts linking early childhood nutrition — especially birth weight and improved patterns of linear growth — with long-term outcomes. They have clear implications for public-health policy and nutrition interventions."

Dr. Adair and colleagues agree. "Individuals in the cohorts that we studied were born when poor early-life nutrition was more common than it is now, which is shown by the high prevalence of stunting during infancy." But mortality and undernutrition are falling substantially in most parts of the world, with the exception of sub-Saharan Africa, they explain, so the individuals they studied grew up in rapidly changing environments that fostered development of obesity and chronic disease risk.

The results therefore challenge several programs in such countries, they say. For example, "traditional school feeding programs that increase [body mass index] BMI with little effect on height might be doing more harm than good in terms of future health."

"Countries that are challenged by the dual burden of persistent undernutrition and emerging obesity need information about the many effects of early child growth," they observe.

Need for New Ways to Promote Height Growth

Dr. Adair and colleagues used data from 5 prospective birth cohort studies from the 5 countries and examined BMI, systolic and diastolic blood pressure, plasma glucose concentration, height, years of attained schooling, and related categorical indicators of adverse outcomes in young adults. They assessed how these outcomes relate to birth weight and to statistically independent measures representing linear growth (height) and weight gain independent of linear growth (relative weight gain) in 3 age periods: 0 to 2 years, 2 years to mid-childhood, and mid-childhood to adulthood.

They obtained information from 8362 participants who had at least 1 adult outcome of interest. Higher birth weight was associated with an adult BMI of greater than 25 kg/m² (odds ratio [OR], 1.28) and a reduced likelihood of short stature (0.49) and of not completing secondary school (0.82).

Faster relative weight gain was associated with an increased risk for adult overweight (age 2 years: OR, 1.51, 95% confidence interval [CI], 1.43 – 1.60; mid-childhood: OR, 1.76, 95% CI 1.69 – 1.91) and elevated blood pressure (age 2 years: OR, 1.07; mid-childhood: OR, 1.22).

Although higher birth weight was associated with a greater likelihood of overweight in adulthood, this was mostly fat-free mass, the researchers explain. "Birth weight and faster conditional relative weight gain in the first 2 years of life had little relation with adult cardiometabolic disease risk factors," they point out. In contrast, "Adverse associations with fast relative weight gain are largely confined to mid-childhood and adulthood."

Faster linear growth was also strongly associated with reduced likelihood of short adult stature (age 2 years: OR, 0.23; mid-childhood: OR, 0.39) and of not completing secondary school (age 2 years: OR, 0.74; mid-childhood: OR, 0.87).

"Finding ways to get very small children to be taller has proved elusive, and we don't really know how to do it," Dr. Fall said. More work is needed on imaginative interventions to specifically promote height growth, instead of weight gain, she noted. These could include exclusive breast-feeding, high-quality protein, and micronutrients, she and her colleagues conclude.

Dr. Adair and colleagues have disclosed no relevant financial relationships. Dr. Bhutta has disclosed no relevant financial relationships.

Lancet .Published online March 28. Abstract