All the available evidence indicates that the incidence of dental caries is related to the frequency of ingestion of sugars. However, the influence of varying intervals between exposure to sugars while keeping the total number of exposures constant is less clear. It was observed that animals that ingested a total of 17 meals daily for 5 weeks at intervals of 10 or 20 min developed approximately 50% fewer lesions than did the animals consuming the same number of meals at 40- and 60-min intervals. Animals which had the highest caries scores harbored the most Streptococcus mutans. Weight gains in all groups were similar, indicating that weight gain alone is not necessarily a reliable indicator of eating patterns.