This all really depends on the person. I suggest planning out all meals so you don't have the temptation to "snack."
I eat 3 meals every day at work and 3 outside work, and these are all altered regularly depending if I'm trying to gain or lose weight. About 80% of the time I'm trying to gain, but I still structure meals consistently so I know what is/isn't working.
A standard day would be -
5 a.m. - 3 eggs, 3 egg whites, 1.5 pieces Ezekiel bread
8 a.m. (Work) - 2 scoops whey protein 1 serving oatmeal
11:30 a.m. (Work) - 8 oz meat, 1 cup rice
3 p.m. (Work) - same as 11:30
6 p.m. - 2 scoops protein, maybe a pickle if I'm hungry
8:30 p.m. - 8 oz chicken/beef, side salad
My wife prepares and packages all these, and she eats the same, just 1/3 to 1/2 as much.
I've been eating like this for about 6 years. I miss a meal maybe once or twice a month, and do "cheat"'occasionally as I enjoy food. I've found that by being consistent you can figure out exactly what does and doesn't work and how to adjust for energy, muscle mass, fat, etc. Food is one of the strongest tools for your body and mind.
Sorry for the tangent, I'm obviously very passionate about this lol.