Macronutrients are just things like carbohydrates, fats and proteins. All are necessary, and none are evil per se. To summarize:
Carbohydrates ("carbs"). Despite what you may have heard, these are not evil. They are a necessary source of energy for your body. The problem is that people over-consume certain sources of carbohydrates, most notably simple sugars from soda and candy, and starches from white bread. If you have to cut down on one macronutrient, cut down on carbohydrates. People in Western cultures consume far too many carbohydrates on average.
Proteins. These are necessary for your body to maintain its muscles, repair damage to them, and generally hold itself together. Most people get enough protein, though an intense exercise program may call for eating more for optimal results. If you cannot manage to take enough protein into your diet, protein powder may be the key. TrueProtein sells among the cheapest and also highest quality protein powders (you can also use the code LMR104 when checking out for an extra 5-10% off). Optimum Nutrition is another well-recommended powder.
Fats. Fats are not evil, either. Eating dietary fat does not mean that body fat will instantly appear on your gut or ass; your body doesn't work that way. Fats perform a variety of necessary functions. The problem is that people over-consume saturated fats and trans fats, which raise LDL ("bad") cholesterol and lower HDL ("good") cholesterol, and under-consume healthy fats like monounsaturated fats (found in high concentrations in olive oil and canola oil) and Omega-3 fatty acids (found in fish, flax seed oil and other sources). Fats also have more calories ounce-for-ounce than carbohydrates and proteins, making very high fat foods astoundingly calorie-dense.
There is some disagreement over what the ideal ratio of carbohydrate to fats to protein in a person's diet should be. In fact, one recent study is now showing that this ratio matters much less than previously thought. For most people, something in the neighborhood of 40% carbohydrate calories/30% protein calories/30% fat calories would be about the right ballpark, with approximately 1/3 of your fat calories coming from each type of fat (saturated, polyunsaturated, and monounsaturated). The general population skews towards lower protein, and more carbohydrates and fat, and more importantly tend to get their carbs and proteins from unhealthy sources.
Alcohol. Technically a macronutrient, though most people don't think of it that way. Alcohol itself has calories, and some alcoholic drinks are very calorie-dense due to their sugar content. If there's anything like a useless source of calories, alcohol is it. Alcohol consumption has been consistently shown to result in sustained, significant decreases in testosterone and growth hormone levels. In addition, it also directly inhibits how the body processes proteins. If you're trying to build muscle, it is best to cut down on alcohol consumption.
Cholesterol: I'm including this here as a subset of fats, though technically it isn't a macronutrient. Cholesterol in food does not directly translate in into high blood cholesterol for most people. For those with high cholesterol, specifically high LDL ("bad") cholesterol, focus on cutting saturated and trans fats, which contribute to cholesterol production in the liver.
Dietary fiber: This is a subset of carbohydrates, though people don't usually think of fiber that way. Dietary fiber has many health benefits, and almost everyone should eat more of it.
Water: Drink more water. Water regulates virtually every bodily process in some way. Drinking more water is a simple, virtually cost-free thing you can do to improve your overall health. Also, if you drink water, you aren't drinking calories, and will feel fuller. Finally, drinking plenty of water is essential to getting the most out of your workouts in a safe manner. The recommended amount differs from person to person (If you've heard anything about 8 glasses a day, it's bunk), but there's no danger in drinking more.
by: sean10mm & liamrosen