Scientists looked at 15 different studies involving nearly 37,000 children in poorer countries to see if a special nutrient supplement helps kids grow better. Instead of using the usual math formula to measure growth, they tried a simpler approach: figuring out what age a child’s height matches. They found the supplements helped kids grow about 12 extra days worth of height per year, but the effect was modest—only about 11% of what perfect growth would look like. This new measurement method might help doctors better understand if growth supplements are actually working.

The Quick Take

  • What they studied: Whether a new way of measuring child growth (called ‘height-age’) works better than the old method for understanding if nutrient supplements help kids grow taller
  • Who participated: Nearly 37,000 children from 15 different studies across 10 low- and middle-income countries. The children were not growing at normal rates and received either a special nutrient supplement or no supplement
  • Key finding: Children who got the nutrient supplement grew about 12 extra days worth of height per year compared to children who didn’t get it. Using the new measurement method, the supplement helped kids achieve about 11% of what perfect growth would be
  • What it means for you: The supplement appears to help children grow somewhat better, but the improvement is modest. This new way of measuring growth might help parents and doctors better understand whether growth supplements are actually working. However, more research is needed before doctors widely use this new measurement method

The Research Details

Scientists combined results from 15 different research studies that tested whether a special nutrient supplement (made from oils and other nutrients) helps children grow taller. Each study randomly gave some children the supplement and other children no supplement, which is the gold standard way to test if something works. The researchers then looked at all the results together to find patterns.

Instead of just using the standard math formula (called z-scores) that doctors normally use, they tried a new approach. They figured out what age a child’s height matched. For example, if a 3-year-old was only as tall as a typical 2-year-old, they said that child’s ‘height-age’ was 2 years. They then calculated how much the supplement improved this height-age compared to children who didn’t get it.

The researchers also created a new measurement called ‘proportion of maximal benefit’ (PMB) that shows what percentage of perfect growth the supplement helped achieve. This makes it easier to understand the real-world impact of the supplement.

The old way of measuring growth (z-scores) uses complicated math that’s hard for regular people to understand. A parent might hear ’the supplement improved z-scores by 0.15’ but have no idea what that means in real terms. The new height-age method is much simpler—it tells you exactly how many days or months of extra growth a child got. This makes it easier for parents, doctors, and health workers to decide if a supplement is worth using

This study combined results from 15 well-designed research studies, which is a strong approach. The studies included almost 37,000 children, which is a large number. However, the results varied quite a bit between different studies (the researchers found 90% variation), which means the supplement might work better in some places than others. The researchers were honest about this limitation. The new measurement method (height-age and PMB) is new and still needs more testing to make sure it’s reliable

What the Results Show

When researchers combined all 15 studies, children who received the nutrient supplement grew about 12 extra days per year compared to children who didn’t get the supplement. This might sound small, but over several years it adds up. Using the old measurement method (z-scores), the supplement improved growth by 0.15 points, which matched up well with the height-age finding.

The new ‘proportion of maximal benefit’ measurement showed that the supplement helped children achieve about 11% of what perfect, healthy growth would look like. In other words, if perfect growth would add 100 days of height per year, this supplement added about 11 days. This tells us the supplement helps, but it’s not a complete solution to growth problems.

The researchers found that the two measurement methods (the old z-score method and the new height-age method) gave very similar results, which is good news. It means the new method works similarly to the old one but is easier to understand. However, there was a lot of variation between different studies—some showed bigger benefits than others—which suggests the supplement might work better in some situations or countries than in others.

The researchers noticed that when they removed one study that had very different results from the others, the two measurement methods matched up even better (correlation went from 0.74 to 0.94). This suggests that most studies were consistent with each other, but one study was an outlier. The large amount of variation between studies (90%) is important because it means the supplement’s effectiveness might depend on things like local food availability, how well the supplement was given to children, or differences in the children studied

This is the first study to test whether the new ‘height-age’ and ‘proportion of maximal benefit’ methods work for measuring growth in nutrition studies. Previous research has shown that nutrient supplements help children grow somewhat better, but doctors have always used the complicated z-score method to measure this. This study shows that the new, simpler method gives similar results to the old method, which is encouraging. However, the researchers note that more studies are needed to confirm that this new method is truly useful for comparing different supplements and interventions

The biggest limitation is that results varied a lot between the 15 different studies (90% variation), which means we can’t be completely sure the supplement works the same way everywhere. The researchers don’t fully explain why some studies showed bigger benefits than others. Additionally, the new measurement methods (height-age and PMB) are brand new and haven’t been tested in many other studies yet, so we don’t know if they’ll work well for all types of growth studies. The study also only looked at one type of supplement (small-quantity lipid-based nutrient supplements), so we don’t know if these new measurement methods would work for other types of supplements or interventions

The Bottom Line

Based on this research, nutrient supplements appear to provide modest help with child growth in low- and middle-income countries (Moderate confidence). The supplements helped children grow about 12 extra days per year, which is helpful but not a complete solution. These supplements may be worth considering as part of a broader approach to improving child nutrition, along with other strategies like better food access and healthcare. However, parents and health workers should have realistic expectations—the supplements help, but they’re not a miracle cure (Low to Moderate confidence in the new measurement method itself, since it’s brand new)

This research matters most for children in low- and middle-income countries who are not growing at normal rates. It’s relevant for parents, doctors, health workers, and organizations that work on child nutrition in these areas. The new measurement method (height-age) might be especially useful for health workers who don’t have access to computers or complicated calculations. However, this research is less relevant for children in wealthy countries who have good nutrition and healthcare. The findings don’t apply to healthy children with normal growth

If a child starts taking this supplement, you probably wouldn’t notice a big difference in just a few weeks. The studies measured growth over several months to years. Based on the research, you might expect to see about 12 extra days of growth per year, which means a child might be about 1 centimeter taller per year than they would have been without the supplement. Real improvements in growth take time and require consistent use of the supplement

Want to Apply This Research?

  • Track child’s height monthly using the same measuring technique (barefoot, against a wall, at the same time of day). Record the exact measurement in centimeters. Compare measurements month-to-month to see if growth is improving. If using the supplement, track whether it’s being given consistently (daily or as recommended)
  • Set a daily reminder to give the supplement at the same time each day (such as with breakfast). Use the app to log each time the supplement is given. Take a monthly photo of the child standing against a marked wall to visually track growth progress. Set a goal to measure height on the same day each month
  • Create a growth chart in the app that shows height measurements over 6-12 months. Compare the child’s growth rate before starting the supplement to growth rate after starting it. Track supplement adherence (how many days per week it was actually given). Share monthly measurements with a healthcare provider to ensure the child is growing at an acceptable rate. If growth isn’t improving after 3-6 months of consistent supplement use, discuss with a doctor whether other factors might be affecting growth

This research summary is for educational purposes only and should not replace professional medical advice. The findings apply specifically to children in low- and middle-income countries who are not growing at normal rates. Before starting any supplement for a child, consult with a pediatrician or healthcare provider who can evaluate your child’s individual health needs. The new measurement methods discussed (height-age and proportion of maximal benefit) are still being researched and are not yet standard clinical practice. Growth problems can have many causes, and supplements alone may not be sufficient—a healthcare provider should evaluate the child for other potential causes of poor growth. This summary reflects research published in October 2025 and may not include more recent findings.