Not only the quality of the food but the quantity. Even if you have the best foods available in a biome, if you wait until each food slot times out (empties) to eat the replacement you're gimping yourself badly. Time to replenish is when the start blinking. You might get away with slacking a bit on that if you're in a 'safe' biome doing 'safe' chores.. then again.. "The ground is shaking".