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With research staff from more than 60 countries, and offices across the globe, IFPRI provides research-based policy solutions to sustainably reduce poverty and end hunger and malnutrition in developing countries.

Erick Boy

researcher spotlight

Erick Boy

Erick Boy is the Chief Nutritionist in the HarvestPlus section of the Innovation Policy and Scaling Unit. As head of nutrition for the HarvestPlus Program since 2008, he has led research that has generated scientific evidence on biofortified staple crops as efficacious and effective interventions to help address iron, vitamin A, and zinc deficiency in sub-Saharan Africa, Latin America, and South Asia.

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experts

Nutrition, Diets, and Health

Jef L. Leroy

Senior Research Fellow

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Bio

Jef Leroy is a Senior Research Fellow in the Nutrition, Diets, and Health Unit, where he studies the impact of nutrition-sensitive agriculture and social protection programs on maternal and child nutrition. His evaluation studies use experimental designs combined with process evaluations and costing studies. Jef currently works on the evaluation of a social protection program in Bangladesh designed to improve birth outcomes and on the evaluation of a training and certification program aimed at improving the quality of milk sold by informal vendors in Nairobi. In addition, he studies the role of food environments in adolescent nutrition in urban areas in Ghana, Viet Nam, and Ethiopia and conducts research on child wasting and on the use of child linear growth in development.

Jef recently completed the evaluation of two large-scale food-assisted maternal and child health and nutrition programs in Burundi and Guatemala. His previous research focused on the impact of aflatoxin on child linear growth in Kenya and Mexico. Before joining IFPRI, Jef was a research associate in the Center for Evaluation Research and Surveys at Mexico’s National Institute of Public Health, where he worked on the evaluation of the urban and rural Oportunidades programs and of the Programa de Apoyo Alimentario (a cash and in-kind transfer program).

Jef, a Belgian citizen, has a PhD in international nutrition from Cornell University, US, and an MSc in agricultural and applied biological sciences from Ghent University, Belgium.

Languages: Dutch, English, French, Spanish

Google Scholar Profile

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CV

Publications

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Book Chapter

Nutrition and diets: Research and action, looking back to move forward

2025Gillespie, Stuart; Ruel, Marie T.; Leroy, Jef L.; Olney, Deanna K.; Singhkumarwong, Anusara
Details

Nutrition and diets: Research and action, looking back to move forward

The last half-century has seen major changes in the nature of malnutrition around the world, as well as in our understanding of its manifestations and key drivers, the people most affected, and the policies and programs developed to address it. This chapter reviews the evolution of nutrition in both policy and programming, with particular attention to agriculture, food systems, and multisectoral approaches, before looking to future directions for nutrition policy, programming, and research. Book link: https://hdl.handle.net/10568/174108

Year published

2025

Authors

Gillespie, Stuart; Ruel, Marie T.; Leroy, Jef L.; Olney, Deanna K.; Singhkumarwong, Anusara

Citation

Gillespie, Stuart; Ruel, Marie T.; Leroy, Jef L.; Olney, Deanna K.; and Singhkumarwong, Anusara. 2025. Nutrition and diets: Research and action, looking back to move forward. In Global food policy report 2025: Food policy: Lessons and priorities for a changing world, eds. Johan Swinnen and Christopher Barrett. Part Four: Transforming Lives and Livelihoods, Chapter 12, Pp. 293-316. Washington, DC: International Food Policy Research Institute. https://hdl.handle.net/10568/174305

Keywords

Nutrition; Diet; Research; Nutrition Policies; Public Policies; Health; Food Systems; Nutrition-sensitive Agriculture

Language

English

Access/Licence

Open AccessCC-BY-4.0

Source

Source record

Record type

Book Chapter

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Journal Article

Adoption or placement in foster care and catch-up in linear growth and development: A meta-analysis of individual participant data

2025Leroy, Jef L.; Angel, Moira Donahue; Frongillo, Edward A.
Details

Adoption or placement in foster care and catch-up in linear growth and development: A meta-analysis of individual participant data

Background The ability of children to recover from linear growth retardation, often referred to as catch-up growth, has intrigued researchers for many decades. Whether adoption from a low-to a high-income setting, which provides a comprehensive improvement in the conditions that cause children to not grow well, leads to catch-up growth is unknown. Objective We estimated the association of adoption (or placement in foster care) with catch-up in linear growth and child development before 5 years of age. Methods We conducted a two-stage meta-analysis using individual participant data for linear growth. We obtained study-specific and subgroup estimates and pooled the estimates using random-effects models. Sensitivity analyses were used to assess the robustness of our findings. A review of child development outcomes was conducted. Results We included 485 children under 5 years of age from 9 adoption studies. At baseline, children had a mean age of 15.8 mo and a length deficit of 3.9 cm. Adoption reduced this gap by 77% or 3.0 cm (95% CI: 1.9-4.1 cm)(mean age 32.3 mo). Catch-up growth was found in both girls (3.6 cm; 95% CI 2.9-4.2 cm) and boys (2.5 cm; 95% CI: 1.9-3.1 cm) and in children adopted after the age of 24 mo (2.2 cm, 95% CI 0.6-3.7 cm). The sensitivity analyses did not change any of the substantive findings. The magnitude of catch-up in child development (mean reduction in deficit of 46%) was smaller than in linear growth. Conclusions Catch-up in linear growth in children under five is biologically possible when the environment is improved profoundly and comprehensively. Partial reversal of the accumulated height deficit was more likely than recovery in developmental outcomes which highlights the need to ensure all children grow and develop in environments that prevent deficits from occurring rather than trying to correct them.

Year published

2025

Authors

Leroy, Jef L.; Angel, Moira Donahue; Frongillo, Edward A.

Citation

Leroy, Jef L.; Angel, Moira Donahue; and Frongillo, Edward A. 2025. Adoption or placement in foster care and catch-up in linear growth and development: A meta-analysis of individual participant data. Advances in Nutrition 16(4): 100395. https://doi.org/10.1016/j.advnut.2025.100395

Keywords

Child Development; Children; Growth; Stunting

Language

English

Access/Licence

Open AccessCC-BY-4.0

Links

https://doi.org/10.1016/j.advnut.2025.100395 Source record

Project

Agriculture for Nutrition and Health

Record type

Journal Article

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Journal Article

Perspective: Can growth monitoring and promotion accurately diagnose or screen for inadequate growth of individual children? A critical review of the epidemiological foundations

2025Leroy, Jef L.; Brander, Rebecca L.; Frongillo, Edward A.; Larson, Leila M.; Ruel, Marie T.; Avula, Rasmi
Details

Perspective: Can growth monitoring and promotion accurately diagnose or screen for inadequate growth of individual children? A critical review of the epidemiological foundations

Growth monitoring and promotion (GMP), the process of periodic anthropometric measurements to assess the adequacy of individual child growth, is implemented across low- and middle-income countries (LMICs). The epidemiological foundations of GMP (i.e., that GMP can accurately diagnose or screen for inadequate growth) have never been critically reviewed. We first assessed growth patterns of individual healthy children. Using longitudinal data from low-, middle-, and high-income countries, we evaluated whether commonly used GMP criteria can be used for diagnosis and screening; i.e., if they accurately identify current, or predict subsequent, inadequate growth in individual children. The growth of individual healthy children does not track along a specific growth curve which challenges the notion that growth measurements alone can be used to distinguish between healthy and inadequate growth. We demonstrate that GMP criteria do not provide meaningful diagnostic information and that GMP is not a meaningful screening activity: commonly used GMP criteria are inaccurate predictors of (inadequate) growth later in childhood; and collecting individual children’s weight and height does not help to identify who needs support or who will benefit. Our results do not undermine the importance of dedicated programs to diagnose wasting in individual children nor do they challenge the need for well-child care to support parents and to ensure children’s optimal nutrition, health, and development. Our findings, however, highlight the need to carefully reconsider the current design of GMP in LMICs.

Year published

2025

Authors

Leroy, Jef L.; Brander, Rebecca L.; Frongillo, Edward A.; Larson, Leila M.; Ruel, Marie T.; Avula, Rasmi

Citation

Leroy, Jef L.; Brander, Rebecca L.; Frongillo, Edward A.; Larson, Leila M.; Ruel, Marie T.; and Avula, Rasmi. 2025. Perspective: Can growth monitoring and promotion accurately diagnose or screen for inadequate growth of individual children? A critical review of the epidemiological foundations. Advances in Nutrition 16(3): 100367. https://doi.org/10.1016/j.advnut.2025.100367

Keywords

Child Growth; Diagnosis; Epidemiology; Screening; Stunting; Undernutrition; Wasting

Language

English

Access/Licence

Open AccessCC-BY-4.0

Links

https://doi.org/10.1016/j.advnut.2025.100367 Source record

Record type

Journal Article

Blogs

What are kids watching online? How digital food marketing shapes children’s and adolescents’ diets
IFPRI Blog
 | 
April 03, 2025

What are kids watching online? How digital food marketing shapes children’s and adolescents’ diets

By Gabriela Fretes and Jef L. Leroy

A study shows the influence of social media.

Rethinking growth monitoring and promotion in low- and middle-income countries
IFPRI Blog
 | 
March 05, 2025

Rethinking growth monitoring and promotion in low- and middle-income countries

By Jef L. Leroy, Rebecca Brander, Edward A. Frongillo, Leila M. Larson, Marie Ruel, and Rasmi Avula

A study raises questions about a standard practice.

Evaluating impacts: Lessons from food systems interventions across Africa and Asia
IFPRI Blog
 | 
July 16, 2024

Evaluating impacts: Lessons from food systems interventions across Africa and Asia

By Jef L. Leroy, Lynnette Neufeld, Stella Nordhagen, and Sydney Honeycutt

Transforming food systems is promising but complex, requiring strong evidence and rigorous evaluations to ensure effective interventions.

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Events

IFPRI @ CGIAR Science Week
IFPRI at External Event

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April 7 to 12, 2025

IFPRI @ CGIAR Science Week

When humanity has faced its greatest challenges, science and innovation have provided solutions. Today, major and connected global challenges threaten the sustainability of food, land, and water systems, with the most vulnerable people and communities at greatest risk. Recognizing the urgency of these challenges, CGIAR and the Kenyan Agricultural and Livestock Research Organization (KALRO) are […]

Improving Diets and Nutrition through Food Systems: What Will it Take? A Dialogue on IFPRI’s 2024 Global Food Policy Report
Series/Special Event

 | 

November 6, 2024, 1:00 – 5:00 pm

Improving Diets and Nutrition through Food Systems: What Will it Take? A Dialogue on IFPRI’s 2024 Global Food Policy Report

IFPRI’s 2024 Global Food Policy flagship publication arrives at a pivotal moment, as the importance of addressing food systems for better nutrition continues to gain global recognition. With United Nations Framework Convention on Climate Change (UNFCCC) 29th Conference of the Parties taking place in November, the SUN Global Gathering on the horizon and the Nutrition […]

NUTRITION 2024: Where the best in science & health meet
IFPRI at External Event

 | 

June 29 to July 2, 2024

NUTRITION 2024: Where the best in science & health meet

IFPRI is pleased to participate in the NUTRITION 2024 conference. The conference program will feature scientific symposia and educational sessions, unpublished oral research study presentations, poster sessions and flash talks. As well as award lectures delivered by distinguished leaders, professional and career development opportunities, and events with ASN’s vibrant scientific communities known as Groups Engaging […]

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News

February 20, 2025 | Press Release

New study challenges the use of Growth Monitoring and Promotion to detect growth faltering in children

A new study published in Advances in Nutrition critically examines the effectiveness of Growth Monitoring and Promotion (GMP) in diagnosing or screening for inadequate growth in children.

December 10, 2020 | In the News

Covid-19 and the irreversible marks undernutrition will leave in its wake (Poshan Outlook)

Poshan Outlook (India) published an op-ed by Poverty, Heath, and Nutrition Division Director Marie Ruel and Senior Research Fellow, Jef Leroy that stated one of the key objectives of India’s Covid-19 mitigation efforts is to prevent child undernutrition now rather than to treat it later, without compromising on maternal, child health and nutrition services. What started as a health crisis has developed into a […]

September 09, 2019 | In the News

Guatemalans grew an inch in half a century (Prensa Libre)

Guatemala’s Prensa Libre reported on the recent finding that Guatemalan women’s average height has increased an average of one centimeter over the past fifty years, making them the shortest female population in the world. The article explained the connections between stature and other indicators of health and quality of life and quoted Senior Research Fellow […]

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