What can a program do to assure that care is always being taken for the health safety and nutritional status of each infant and toddler?

It depends on what type of "program". In the best case, a program should be equipped to assess:

1. head circumference of infants, and compare to national medical standards
2. the length of infants - compare to standards
3. weight of each infant and child - compare to standards
4. dehydration status
5. mouth-tongue-teeth status - problems can interfere with eating healthy, for example, oral thrush in babies
6. parent's understanding of nutrition and a nutritional meal plan
7. meal planning in the home
8. avoidance of fast "weight loss" schemes
9. instruction that babies do not need weight loss diets
10. instruction that children need exercise, not weight loss pills or fad diets
11. parents' ability to eat healthy themselves