We get a lot of different messages about how much food to eat -- and most of us are out of touch with our hunger, either eating when we're not hungry, eating even if we're full, or not eating until we're completely starving.
There are a few Ayurvedic principles that can guide us to eating in a way that makes our digestion more complete and efficient, and maintain our energy throughout the day. Good digestion is THE most important aspect of eating. It's actually better to digest bad food well than it is to eat good food but digest it poorly. Several things affect our digestion, and quantity is one of them.
Imagine a cereal bowl. Your whole meal should fit into the bowl, as it represents your stomach's physical capacity. Mentally divide it into 3 equal portions. The first portion represents how much of the meal should be liquid, preferably in the form of soup. The second portion represents the amount of solid food you consume. And guess what the third portion represents... nothing! You should leave that much empty space in your bowl/stomach to allow room for proper digestion. You won't be left hungry, but you won't be full.
Snacking is healthy as long as there is at least a 2 hour resting period between putting things in your mouth, and 4 hours before going to bed. Again, all to ensure that what we do eat has time to digest properly. Different mind/body constitutions do better with different kinds of snacks, and I'll post all about that in the near future.
Another principle to know when to eat is to imagine a scale of 1 to 10, with 1 being absolutely famished and 10 being I'm-going-to-explode full. When you're at about a 3 is a good time to eat, and stop when you're at about a 7 (or you've finished your bowl's worth of food). Sounds reasonable, doesn't it?