This study investigates seasonal variation in energy intake among rural lowland rice farming households in Madagascar’s Central Highlands. Using a three-round panel dataset collected across the harvest (June), postharvest (October), and lean (February) seasons, we assess changes in total caloric intake and energy sufficiency at the individual level. Household food consumption data, collected via 24-hour recall, were converted to adult male equivalent caloric values and analyzed using fixed effects regression. Results show a consistent energy deficit across all seasons, with a significant decline during the lean season: Average energy intake falls from 2018 kcal in June to 1926 kcal in February, corresponding to a 5% point drop in sufficiency. As rice stocks dwindle, households increasingly rely on purchased staples and substitute roots and tubers for rice. However, dietary diversification remains limited, and animal-source food consumption is persistently low. These findings highlight the importance of seasonal dynamics in shaping food security and call for nutrition-sensitive interventions tailored to periods of heightened vulnerability. Potential strategies include targeted support during the lean season, improved postharvest storage, and promotion of culturally acceptable alternative staples. Addressing seasonal food insecurity is essential for building resilience among Madagascar’s rural farmers.