Effects of dietary supplementation on work performance in Gambian laborers.
The effect of food supplementation on productivity of Gambian subsistence farmers was studied during a natural food shortage induced by the annual hungry season. Sixteen men in two groups matched for weight, height, hemoglobin, and physical-work capacity followed a crossover protocol with 6-wk supplementation and control periods. Productivity was assessed over the final 3 wk of each period by quantifying piece-rate-paid road building. Supplementation comprised an ad libitum supply of highly palatable energy-dense food provided three times daily. Outcome variables were total loads transported, loads per working hour, time per load, total energy expenditure assessed by doubly labeled water and heart-rate monitoring, postwork activity, and anthropometry. Body weight decreased during control periods, indicating a real energy deficit, and increased during supplementation in both groups. Supplementation had no significant impact on productivity variables. Energy-deficient men can maintain maximal productivity over short periods if sufficiently motivated but at the expense of body weight.
Diaz
E
E
MRC Dunn Nutrition Unit, Cambridge, UK.
Goldberg
G R
GR
Taylor
M
M
Savage
J M
JM
Sellen
D
D
Coward
W A
WA
Prentice
A M
AM
D000328:Adult; D001481:Basal Metabolism; D001835:Body Weight; D004032:Diet; D004040:Dietary Carbohydrates / Q000008:administration & dosage; D004041:Dietary Fats / Q000008:administration & dosage; D004044:Dietary Proteins / Q000008:administration & dosage; D004734:Energy Metabolism; D005714:Gambia; D006339:Heart Rate; D006801:Humans; D008297:Male; D005082:Physical Exertion / Q000502:physiology*; D014937:Work
D004040:Dietary Carbohydrates; D004041:Dietary Fats; D004044:Dietary Proteins