Perceived food need is determined by many things... including your social conditioning.
Actual need can be, and often is, quite different...
This assuming one can discern between the feelings of hunger and thirst... which many people cannot seem to do anymore due to confusion/disturbances in signaling.
Studies have shown that animals with a sterile gut, or lacking adequate microflora crave, need, and consume more food and calories than another that has a healthy gut microflora...
This is likely due to several reasons, including better nutrient absorption, energy creation, and more complete digestion in those with a healthy microflora.
I have been focusing my efforts of late on gut terrain and microflora support... and can tell you that appetite does change... as does what you desire to eat.
All this holiday season, I have primarily ate vegetables, some nuts, and my raw dairy... had absolutely no desire for the deserts, candies, etc... none.
The two deserts I have had since T-day this season were more because of tradition; I also knew what went into them.
I had one rather medium sized lunch today about 2 P.M. Over the course of the day I have also had two herbal teas and a serving of kefir. It is now after 7 P.M. and I have absolutely NO desire to eat at all... and still feel very full/satisfied.
Is this an indication that one meal per day is all that we may need? No, it is not...
When my activity level goes up, I desire to eat more frequently, but not necessarily more; so it is usually close to the same amount I ate today... just spread out over time a bit more.
And, what I crave may change... usually a bit more quality protein and healthy fat - a handful of raw nuts perhaps. The smaller meals during times of higher activity, enables me to engage in the activity without feeling tired, full, or bogged down...
Other's experiences may be different...
If one is eating (sparsely by today's standards) like this though, it is imperative that one ensure nutrient density and high quality in the food they do eat.
It is not too difficult to justify the cost of purchasing, or growing/raising better quality food, if one is eating so much less that the cost becomes a wash.
Calories is not what it is about... it is about the ability to "create" energy from the food you eat.
The alkaline minerals found in high quality foods, regardless of any caloric value, have a greater energy producing potential in the gut when they react with the organic acids produced by gut microflora... producing energies for the host.
I think that the fixation on calories in diet is all wrong... even in the caloric reduction and longevity studies the model ensures adequate nutrition to the calorie restricted group... indicating that nutritional value is extremely important.