I really like this question. Definitely, there is a correlation between body and mind. And IMO there are two factors to consider.

1. The more energy food has in itself, the more energy you will feel in your body and therefore in your mind.
2. If you eat food that you think is good for you, you will be in alignment with what you eat (even if you eat something that may appear as "bad food" to other people.) So your thoughts will be in alignment.

And to be honest, I tend to believe that 2. is immensely more important.

For example I had depression years ago and so I started eating raw, organic, vegan food, hoping that it would raise my mood up somehow. But I didn't really believe in it... I was just hoping that it would help. So my mood got better...but not significantly better.

Whereas three years ago I wanted to lose weight and so I came up with my own diet for weight loss because I got frustrated from all those "healthy" diets that wouldn't work. So I called it "Releaser99's Fast Food Diet". I ate burgers, pizza, pasta and all the things known as junk food all day, every day. During this time I never ate even one veggie or salad (with the expection of tomatoes, onions and lettuce in burgers). I just counted calories and I lost over 45 pounds in 6 month. All the people around me told me that I would probably die or that I would have low energy, get sick etc.

But I really believed in it. And at that time I never felt better before. I worked all day long and in the evening and night I also worked out in the gym. My skin got clearer, my mood went up, I needed less sleep etc...

So I think that healthy food has value and can be a good permission slip. But I think our thoughts about what we eat are even more important.

Eat what you truly believe is right and you will feel amazing. Eat what you truly believe is bad, and you will feel bad. And it doesn't matter if it's raw organic vegetables or junk food.

apart from 15 minutes of breathing exercises

In my experience we shouldn't underestimate the power of vibrational work. Sometimes 15 minutes of meditation can be worth more than any other action we take in a whole week. When I do vibrational work regularly I don't even notice that I feel better and better and better...Then I get inspired to take aligned action. And often at this point it is easy to believe that it is the action that makes things happen, when it was really the vibrational work in the first place that made the inspired action happen.

Edit: Nikulas, I obviously answered someone else's question in your thread :).

So here is an on-topic edit :).

low emotional state and still maintain high amounts of energy

I think that it is possible. And I agree that it is impossible to feel depressed and powerless when you have high energy. Depression is very low energy by nature. The next question could be: where did the high energy come from in the first place?

As I implied above, I believe that it's impossible to have high energy without aligning thoughts first. And eating the food you think is best will align you with what you believe. This alignment of that one thought raises vibration and gives (high) energy. And this energy is enough to make depression/powerlessness impossible. Maybe anger would be possible. Maybe frustration would be possible. And if you align even more thoughts related to other areas in your life that way, you could move up even higher on the emotional scale (hopefulness, joy etc.).

As a side note: Abraham said that 15 minutes of meditation in the morning makes you almost immune for many low vibrations for the rest of the day.

Gah.. wrote out this answer and computer decided to go on the fritz. Here we go again. =P It appears my higher self still has my short attention span, trying to get my answer to flow like it did the first time isn't quite so easy. ^_^

Being healthy makes positivity easier. Healthy can mean physically, mentally, and spiritually. If your body was receptive to your change in diet it will reward you by making you feel better.

Each of these needs to be nourished, conditioned, disciplined, and cared for. Your body, mind, and spirit are all aspects of your being and proper treatment of any will improve your experience, and make working in the other categories easier as well.

Also, I believe one's diet should be individually tailored to their need at any given time. Sure you can eat the same 'perfect' foods every day, live in a bubble and never encounter any germs, but I personally advise otherwise as part of the 'conditioning' phase of healthy living.

I often feel each of these parts of myself are entities on their own, and when treated properly they let me know by making me feel better, and when neglected they can be quite unruly. If you are attentive they will all speak to you, express their needs and desires, and it's up to you to decide how much of what you deliver them.

I don't think so. Some negative emotions are powerful. For example, Rage is a very powerful emotion and it is similar to excitement. Anxiety is also very powerful it is like the negative side of excitement, so while having a healthy diet may increase energy and positive emotions (for obvious reasons), I don't think increased energy automatically means positive emotions, although it is an influence.

I do not agree with rage being from high energy. rage is emotion cause by outside factor or inner factor. and you are always the one in control. if you are hungry then you might have some rage. hungry and angry rime the mood also go with it. Smile. Your mind set and emotional set are under your control. this belongs to you and no one else. It is the same for every one else. even if other can influence you by their choice. you are the one having the last word on your self. Many I tell you forget this and blame other for their own lack. yet they do not want to be blame so why do it to other? what you would want from other you should give the same. yet people still are blaming, judging and making division. yet 2000 year ago someone said who is with out sin to cast the first stone? and love your neighbor as your self. yet some say that the specie as evolve. Smile. when there is no more division in you, then you will find true peace and will be able to enter the kingdom above. The person old in days won't hesitate to ask a little child seven days old about the place of life, and that person will live. a little child of seven days just told you this.