A resolution to encourage breast-feeding was expected to be approved quickly and easily by the hundreds of government delegates who gathered this spring in Geneva for the United Nations-affiliated World Health Assembly.

Based on decades of research, the resolution says that mother’s milk is healthiest for children and countries should strive to limit the inaccurate or misleading marketing of breast milk substitutes.

Then the United States delegation, embracing the interests of infant formula manufacturers, upended the deliberations.

American officials sought to water down the resolution by removing language that called on governments to “protect, promote and support breast-feeding” and another passage that called on policymakers to restrict the promotion of food products that many experts say can have deleterious effects on young children.