Animal Source Foods Promote Cognitive
Function, School Performance, Increased
Muscle Growth and Activity in Kenyan
Children: From Observational to Evidence-
Based Findings
Charlotte Neumann, UCLA
Nimrod Bwibo, University of Nairobi
Constance Gewa, George Mason University

Evolution of research on malnutrition
and growth and development
• 1970s: protein deficiency
• 1980s-90s: energy deficiency (mild to moderate)
most prevalent nutritional challenge
• 1990s onward: poor diet quality with multiple
micronutrient deficiencies
• 2000s onward: food-based approaches to energy,
protein and micronutrient
deficiencies

Nutritional Benefits of Animal Source
Foods (ASF)1
• Macronutrients
– Relatively high fat content increases energy
density
– High quality complete and readily digestible
protein containing all essential amino acids
– Presence of heme protein enhances iron and
zinc absorption and when mixed with plant foods
– High concentrations of very long chain (vic)
omega 3 and other fatty acids
• Particularly in fish
• Substantial amounts in red meat (beef, pork, lamb,
goat, etc.)
1
meat (of a wide variety), fish, fowl, milk, eggs

Nutritional Benefits of Animal Source
Foods (ASF)1
• Micronutrients (intrinsically high in
meat)
– Zinc and Iron present in bioavailable forms
– Vitamin B12 present almost exclusively in
meat and milk
– Riboflavin
– Lysine
– Calcium, particularly in milk and fish
– Preformed Vitamin A in milk, eggs, and fish
1
meat (of a wide variety), fish, fowl, milk, eggs

Importance of ASF in Developing
Countries
• Infants and young children
– PEM and multiple micronutrient deficiencies
coexist in a high % of children
– Infants weaned onto bulky, dilute, plant-based
dishes with low protein, lysine, and multiple
micronutrient content
• Nonhuman milk consumed in small quantities
• Anemia prevalent due to iron plus other nutritional
deficiencies, parasites, and infection

Importance of ASF in Developing
Countries
• Multiple functional impacts
– Maternal malnutrition with fetal growth restriction and
LWB
– Growth retardation with stunting and reduced lean body
mass
– Impaired resistance to infection with acquired
immunodeficiency
– Cognitive development, physical activity, and
behaviors negatively affected
– Anemia with reduced work capacity and physical activity
– Calcium deficiency
• Rickets in children limiting physical activity
• Osteomalacia in women = pelvic deformity
The addition of meat and animal products can improve/prevent
adverse outcomes.

Nutrition Collaborative Research Support
Program (CRSP)
• Nutrition CRSP awarded to UC Berkeley by USAID
– Three country projects selected for parallel longitudinal
observational studies on mild-moderate energy malnutrition
and human function
• UCLA and U of Nairobi - rural Kenya
• Purdue U, U of Arizona, Nutrition Institute (Cairo), U of
Kansas - semi-rural Egypt
• U of Connecticut, U of Florida, Instituto Nacional de la
Nutricion (Mexico) - rural Mexico
• Forerunner to GLCRSP studies – 1984-1993
– Does mild/moderate energy malnutrition negatively affect
mother-child interactions and care giving, and the child’s
cognitive function, behavior, and physical activity?

Methods
• Longitudinal observational study of infants, toddlers,
schoolers, and biologic parents for one year
• Data obtained:
– Weekly measures
• Morbidity
– Monthly measures
• Quantitative food intake
• Anthropometry, including head circumference and MUAC
– Every 3-6 months measures
• Cognitive testing
• Physical activity measures
– Annual measures
• SES census
• Tested literacy of parents

Some key findings
• Mother-child interactions and child care taking were negatively
affected by low maternal energy intake and anemia
• Shorter and lighter infants and those with poor weight gain were
significantly less sociable, carried more by their mothers, and
had lower motor scores at 6 months than taller and heavier
infants
• Energy intake and meat intake in toddlers (18-30 months) were
positively associated with their Bayley’s test scores and also
predicted their cognitive performance at age 5 years
• Greater physical activity during free play was positively related to
energy meat intake over time in school-aged children
• Better nourished children during free-play were happier and
showed more leadership behavior than less well-nourished
children
• Greater on task behaviors in classroom in the meat group
• The other projects found similar but less striking findings

Study 2 – 1998-present
• Findings from observational studies called for a randomized
controlled intervention study to test the causative role of
dietary meat on:
– cognitive function - physical growth - behavior
– school performance - physical activity - morbidity
• Funding, USAID-Global Livestock CRSP (GLCRSP) – M.W.
Demment, PhD, Director (UC Davis)
– Planning Grant 1997-1998
– A randomized controlled feeding intervention (1998-2003) study
collaborators, UCLA, U of Nairobi, and UC Davis
• PIs: Charlotte Neumann and Nimrod Bwibo
• Co-PIs: Suzanne Murphy and Marian Sigman
• Co-investigators: Lindsay Allen and Shannon Whaley
• The study was carried out in the same area (Embu District)
as the earlier observational study with many of the same staff

Main Hypotheses
Children supplemented with animal foods will:
– Perform better on measures of cognitive function
– Improve school performance (test scores)
– Show improved growth in all dimensions
– Decreased morbidity
– Be more physically active
– Exhibit positive behavior during free-play (leadership,
initiative, etc.)
than those children
Receiving plant-based supplements and the Control
group

Methods
• Randomized, controlled feeding intervention study
of 1st and 2nd grade children to one of four isocaloric
feedings:
– Meat added to githeri*
– Milk with githeri
– Githeri with added oil
– Control; no school feeding
• Two cohorts from the same schools and the same
grades were enrolled exactly one year apart and
each followed for 2 years
– N ~ 500 in cohort 1
– N ~ 375 in cohort 2
*githeri: traditional dish of maize, beans, greens

Methods
• Testing of functional outcome measures:
– Cognitive - Raven’s Progressive Matrices, WISC-R,
Verbal Meaning Test, Digit Span
– Observational Methods for activity and behavior
• Timed observations for 30 minutes/session during free play
• Strictly defined activity levels and behaviors
• Quality control on 15% subsample (high % agreement)
– End term test scores on zone wide examinations
– Morbidity – recall and direct observation
– Growth – anthropometrics (weight, height, MUAC, derived
arm muscle area)
– Biochemical micronutrient status and Hemoglobin
• Independent variables – food intake & malaria status

Selected key findings - Cognitive
• Raven’s Progressive Matrices: Steepest rate of
increase on Raven’s test score in Meat group
(statistically significant)
• Arithmetic skills: the Meat group and the
Githeri group performed significantly better
than Milk and Control groups
• No significant differences were seen in verbal
or digit span

Raven’s Scores
21
20
Raven’s
Control
Scores
Calorie
19
Milk
Meat
18
17
-0.5 0 0.5 1 1.5 2
Relative years in study

School end term test scores
• Meat and Milk groups showed the greatest
increase compared to all other groups in:
– Individual Subject Test Scores (p <0.05)
– Combined Test Scores (p <0.05)
• Scores were controlled for baseline scores,
school, attendance, cognitive scores, gender,
age, SES, height, maternal literacy, home
food intake

Change in Total Test Scores by
Group (over 5 school terms)
*
*
*
*Statistically significant, p < 0.05
Adjusted for age, gender, maternal literacy*, height, home food intake, SES, attendance*

Change in Subject Test Scores by
Group
* *
* *
* * * **
**
* *
* **
*
*
*Statistically significant, p < 0.05
Adjusted for age, gender, maternal literacy*, height, home food intake, SES, attendance*

Change in Subject Test Scores by
Group
(over 5 school terms)
Total
Math English Kiembu Kiswahili Geog. Science Arts Test
Meat *9.37 *5.68 *7.72 3.36 *6.08 -1.47 *9.26 *45.71
Milk *5.74 -1.03 2.97 *5.13 *6.17 -0.66 *6.96 *26.35
Energy 2.26 *-7.58 0.82 *-5.48 -1.53 *-6.66 *4.16 -6.07
Control 3.14 *-9.66 -0.81 *-6.21 *-3.87 *-6.56 *3.31 *-18.67
*Statistically significant, p < 0.05
Adjusted for age, gender, maternal literacy*, height, home food intake, SES, attendance*.

Physical Growth
• Arm muscle area (lean body mass)
– The Meat group showed the steepest and highly
significant gain compared to all other groups
• Weight
– Child who received meat, milk as energy gained
significantly more weight than those in the Control
group
• Height
– No significant differences were seen
– In stunted children and in 6-7 year olds, Milk group
showed better linear growth

ARM MUSCLE AREA (cm2)
githeri plus oil

Physical Activity and Behavior
• Greatest increase in high levels of activity and
on going activity in Meat group
• Greatest decrease in low levels of physical
activity in Meat group
• The Meat group compared to all other groups
showed:
• Greatest increase in initiative
• Greatest increase in leadership
• Greatest increase in peer involvement
• Greatest increase in positive affect

Playground % Initiates

Morbidity
• Control group had the highest illness frequency
occurrences and the least decline over time
• Meat group had the significantly greatest declines in
diarrhea and typhoid occurrences
• Milk group had the significantly greatest decline in
upper respiratory infections
• For malaria and total illnesses, the significantly
greatest declines were seen in the Plain Githeri and
the Meat groups
– The vitamin A fortified oil used in the Plain Githeri
may have reduced morbidity occurrences

Summary
• This first RCT with meat supplementation
shows:
– Increased cognitive and school performance
– Increased high levels of physical activity
– Increased initiative and leadership behaviors
– Increased mid-upper arm muscle area (lean body
mass)
– Decreased morbidity
• All supplemented groups improved overall
weight gain compared to the Control group

Implications
• For optimal learning and school performance children
need diets of adequate quantity and quality
• Improved nutrition quality (through inclusion of
Animal Source Foods) is an investment in human
capital, leadership initiative, and economic
development
• Nutrition is critical for a productive work force
• Findings are also relevant to developed countries
where restrictive vegetarian diets are used, especially
for children
• A sizeable challenge is how to put affordable meat in
the table for the family

Acknowledgment
• Financial support for this project comes
primarily from USAID Grant No. PCE-
G-00-98-00036-00 through the Global
Livestock Collaborative Support Program.
The opinions expressed herein are those
of the authors and do not necessarily
reflect the views of the U.S. Agency for
International Development.