In people trying to loose body weight, cycles of hypophagia followed by hyperphagia are quite common. The aim of the present study was to evaluate the alterations in daily mean arterial pressure (MAP) and heart rate (HR) during short-term (5-day) changes in food intake. Adult male lop-eared rabbits were instrumented for continuous measurement of blood pressure and HR by telemetry (24 hours/day) and fed 150 g/day of maintenance diet. The animals were subjected to five 14-day periods. Each period consisted of 5 days where food intake (normal chow) was randomly set to either 225 g (+50 %), 187 g (+25 %), 112 g (-25 %), 75 g (-50 %) per day or ad libitum, followed by 9 days of recovery at 150 g/day. A 50 % increase in food intake induced an immediate and significant increase in HR and a slight increase in MAP (+24.7 ± 2.8 bpm and +2.2 ± 0.6 mmHg at day 5). Similarly, a 50 % decrease in food intake induced a decrease in HR and MAP (-29.0 ± 1.8 bpm and -5.9 ± 1.3 mmHg at day 5). Food access ad libitum induced an even more pronounced increase in HR and MAP (+43.3 ± 3.9 bpm and +4.4 ± 0.8 mmHg at day 5). Unlike the increase in HR during hyperphagia which reached plateau after 1 day, the decrease in HR during hypophagia was progressive (-29.0 ± 1.8 on day 5 vs. -17.2 ± 2.1 bpm on day 1 of -50 %). The effect of hyperphagia on MAP and HR was reversible within 1 day, except after food ad libitum. Recovery of MAP and HR following hypophagia was rapid, but not complete. Our data suggest that short-term quantitative variations in food intake can lead to pronounced changes in daily hemodynamics, with different courses for hyper- vs. hypophagia. These alterations may play an important role in explaining the increased cardiovascular morbidity associated with weight cyclin
