A few thoughts I want to lay out.
Calories
1 gram carbs = 4 calories
1 gram protein = 4 calories
1 gram fat = 9 calories
1 gram alcoholic sugar = 7 calories
The alcoholic sugars found in spirits are toxic to the body, so your body will seek to remove (burn) these calories first, putting aside all other carbohydrates. That is not to say I am not condoning consumption of refreshing beverages, but keep the consumption in moderation over a period of time. There is nothing wrong with enjoying a one or two servings of beer or wine after work, at the end of the day but keep in mind what alcohol does to the body. Alcohol is also a diuretic, so the water that is lost must be replenished.
The body naturally burns ~2000 calories a day, sometimes more, sometimes less depending on your metabolic rate. The minimum ~1500 calories must be met each day otherwise the body will recognize any deficit as a sign of starvation and will store fat inherently. There is a formula out there to calculate the average number of calories you should consume,
linky, but I personally never had success following the formula. It doesn't take into account the source of the calories, nor the metabolic rate of the individual, and is as misleading as the BMI calculations. In addition, most nutritional panels on the foods you purchase only list the net calories, not the total calories, so just beware when buying your cereal, frozen peas, etc.
To maintain muscle mass, .8 grams per body weight of protein should be consumed, but it is rounded up to 1 gram for ease of calculations. Your body will utilize all the protein it can for muscle repair (after workouts especially) and any excess will be broken down and used as an energy source for your body.
Fat is an important macronutrient to your body. The body can't produce it, similar to protein, and must come from external sources. I try to limit my fat intake and more importantly, my saturated fat intake. For saturated fats, I like to keep the number below 10 grams daily. I try to keep the total fat intake to less than 100 grams, although for everyone else who wants to lose the fat, a lower number is more desirable. Let's say no more than 30% of your calories should come from fat, and no less than 10%.
Some healthy fats include almonds, peanuts, peanut butter, avocados, walnuts, fatty fish/fish oil supplements (omega 3's), flaxseed oil (omega 3's again)
Carbohydrates is the most flexible of the three macronutrients, because your body can survive without external sources. There are two times of the day in which your body can handle carbohydrates optimally, at breakfast time and post workout. Beware of
High Fructose Corn Syrup, avoid at all costs, that means no Gatorade. I rarely eat white bread and other simple carbohydrates, instead I rely more on whole wheat bread (German Dark Wheat is my favorite) and fruits and vegetables for my carbohydrates.
Some tips to try out.
1 - Never eat carbohydrates by themselves, always pair it up with some form of protein.
2 - To keep body fat in check, avoid eating fat and carbohydrates together.
A simple sample of a daily meal plan based on macro nutrition.
Meals 1,2,3 - Carbohydrate + Protein (breakfast, brunch, lunch)
Meals 4.5.6 - Fats + Protein (late afternoon snack, dinner*, bedtime/midnight snack*)
*Feel free to cut down or cut out the fat from these meals if you feel it is not beneficial to your goals.
Hope this helps somewhat, and if any questions come to mind, feel free to ask.
edited for being absent minded.