Explanation of meal plan and exercise plans for a day

Meal plan explanations
Breakfast is usually consumed around 7-9 AM.  However, on certain days, such as whenever I have morning appointments, I consume breakfast much earlier.  On those times, I tend to consume less foods than during the rest of the day.  Common breakfast menus contain cereal, fruits, yogurt, meat, toast, dried fruits, or eggs.

Lunch is usually consumed around 11 AM- 12:30 PM.  This is usually the largest meal of the day.  I wonder if that should be the largest meal of the day since there are times when I consume the most calories, including foods that may be unhealthy.  I should consume no more than 600 calories per meal.  However, I consume over 900-1000+ calories per day.  Now I wonder if I should cut back on lunches in order to balance out my caloric intake for the rest of the day.  This should be for all intents and purposes, the second largest meal of the day.  I guess the caloric intake does not matter according to time of the day, but my diet is not the best and maybe there is a correlation between health and calorie intake.

Dinner is usually consumed around 4-6 PM.  This usually has the same amount of calories as breakfast per day.  I have heard the phrase that means that dinner is usually out of the three main meals the smallest meal of the day.  Usually, dinner is no more than 1/4-1/2 of the calories as lunch.  I also consume the same foods that I eat during lunch.  Maybe it is better that I consume more of a variety of foods.

Snacks are obviously between the meals.  I tend to consume an average of 3-4 snacks per day.  I don't wish to consume foods late at night.  My snacks tend to be healthier than my lunches and dinners.  Snacks in my opinion should not be more than 100-200 calories each.  Sometimes I wonder if my snacks have too many calories.  I need to space out my calories in terms of snacks.  Snacks often include crackers, toast, fruit, dried fruit, or boiled eggs.

Exercise plan explanations:
Good health has always been of great importance to me.  It has worked for my back, neck, and shoulder pain.  Because I exercise, I believe that my health has improved.  I only exercise once a day, but maybe it should be for more than once a day.  I tend to exercise once a day for 15-30 minutes max.  Today, I walked.  I have been walking everyday or at least 5 days a week.  I realize that daily or weekly exercises would do me no good if I don't always eat healthy.  I have learned that diet and HEALTHY eating go a long way.  However, I don't wish to forego exercise just because of fried and fatty foods.  I have noticed changes since I have exercised.