Researchers from the Johns Hopkins Bloomberg School of Public
Health; Cienfuegos, Cuba; and
Loyola University had a unique opportunity to observe the
impact of populationwide weight loss due to
sustained reductions in caloric intake and an increase in
energy output. This situation occurred during
the economic crisis of Cuba in 1989-2000. As a result,
obesity declined, as did deaths attributed to
diabetes, coronary heart disease and stroke. The study was
published Sept. 19 as an Advance Access
study by the American Journal of Epidemiology.
"This is the first, and probably the only, natural
experiment, born of unfortunate
circumstances, where large effects on diabetes,
cardiovascular disease and all-cause mortality have
been related to sustained populationwide weight loss as a
result of increased physical activity and
reduced caloric intake," said Manuel Franco, a doctoral
candidate in the Bloomberg School of Public
Health's Department
of Epidemiology. "Populationwide approaches designed to
reduce caloric intake
and increase physical activity, without affecting
nutritional sufficiency, might be best suited for the
prevention of cardiovascular disease and diabetes."
The study authors gathered data on energy intake, body
weight and physical activity using
previously published literature from the Cuban National
Institute of Hygiene, Epidemiology and
Microbiology; the Food and Agriculture Organization of the
United Nations; the Cuban First and
Second National Surveys on Risk Factors and Chronic
Diseases; and the Cuban Ministry of Public
Health.
There was a drop in the daily per capita food
availability from the late 1980s to 1995, resulting
in a daily energy intake decline from 2,899 kcal in 1988 to
1,863 kcal in 1993. In 1987, 30 percent of
Havana residents were physically active; from 1991 to 1995,
70 percent of Cubans were physically
active as a result of widespread use of bicycles and
walking as means of transportation. Obesity
prevalence in Cienfuegos, Cuba, decreased from 14.3 percent
in 1991 to 7.2 percent in 1995.
During the end of the Cuban economic downturn and the
years following it, there were
substantial declines in cardiovascular disease, type 2
diabetes and all-cause mortality. The
researchers report a plateau in the number of deaths from
diabetes during the food shortage of
1988-96, when physical activity increased and obesity
decreased.
"Future steps toward prevention of cardiovascular
disease and diabetes should focus on long-
term populationwide interventions by encouraging physical
activity and the reduction of caloric intake,"
explained Franco, who is also affiliated with the Johns
Hopkins Welch Center for Prevention and
Epidemiology.
Johns Hopkins researchers Manuel Franco, Benjamin
Caballero, Mariana Lazo and Eliseo Guallar
co-authored the study. Franco was funded by grants from the
Fulbright Commission and the Welch
Center for Prevention, Epidemiology and Clinical Research.
Additional co-authors are Pedro Ordunez,
Jose A. Tapia Granados, Jose Luis Bernal and Richard S.
Cooper.
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