Just as the beginner should stick to the basics in the gym, there’s no reason to complicate the nutrition side of things. In college, nutrition science is its own major and a one-semester course for non-majors. But we’ll assume a) you don’t have four years to dedicate to learning how to eat, b) you currently can’t afford tuition and overpriced textbooks or c) both. So we’ve boiled down the dietary basics to 10 straightforward lessons you need to follow to make sure you put the right foods in your body at the right times.

If you’re serious about making a long-term commitment to fitness, you’ll learn the ins and outs of solid nutrition as you go. But no matter how much information you gather, these fundamental guidelines will always hold true.

1) Consume at least 1 gram of protein per pound of bodyweight daily

Protein provides amino acids, which are the building blocks of muscle protein. Although mainstream nutritional guidelines recommend less than half a gram of protein per pound of bodyweight for the average guy, research shows that athletes — especially those concerned with adding muscle mass and strength — need to roughly double that amount. Beginners should try to get in about 1.5 grams per pound per day for the first six months of training, since this is when your muscles will respond most rapidly. For the 180-pounder, this means 270 grams per day at the outset and a bare minimum of 180 grams daily thereafter.

Your protein choices should mainly animal proteins such as beef, chicken, dairy, eggs, fish and turkey. These are the most complete protein sources, meaning they provide your body with the essential amino acids it can’t manufacture on its own.

2) Get 20%–30% of daily calories from fat

Get this in your head: Fat is not your enemy, especially if you train seriously. Research shows that diets higher in fat (particularly monounsaturated and saturated) appear to maintain testosterone levels better than low-fat diets. Maintaining optimal test levels is paramount for building muscle mass and strength, and avoiding fat gain. And unlike the sedentary general population who are advised to reduce their saturated fat intake, 5%–10% of your fat calories should be from sat fat.

Choose red meats such as ground beef and steak for saturated fat (these also provide quality protein); avocados, flaxseed oil, mixed nuts, olives, olive oil and peanut butter for monounsaturated fats; and fatty fish (catfish, salmon, trout) and walnuts as good sources of essential omega-3 polyunsaturated fats.

3) Consume 20 calories per pound of bodyweight daily

To gain quality mass, you must stay in a positive calorie balance (taking in more calories than you burn). If you burn more calories than you consume, your body will go into conservation mode and won’t support new muscle growth.

Consuming 20 calories per pound means roughly 3,600 calories daily for a 180-pounder. At least 20% and up to 30% of these calories should come from protein, 40%–60% from carbohydrates and the rest from fat.

4) Consume the right amount of carbs for your goals

While protein is the most critical macronutrient for hypertrophy, carbs are a close second. They’re stored in your muscles as glycogen, keep them full and large, and fuel them during workouts. If you’re trying to seriously bulk up, consume 2–3 grams of carbs per pound of bodyweight, or 360–540 grams per day for the 180-pound man.

To maintain your size but fuel intense workouts and improve conditioning, take in 1–2 grams per pound. For fat loss, eat 0.5–1 gram of carbs per pound of bodyweight. For most meals, stick with slow-digesting carbs such as beans, fruit, oatmeal, sweet potatoes, vegetables and whole grains. (For other times of day, see Lesson No. 5.)

5) Eat the right carbs around workouts

As stated in Lesson No. 4, most meals should contain slower-burning carbs. This rule also pertains to your preworkout meal. Research shows that when athletes eat slower- digesting carbs, they not only have more energy and less fatigue during exercise but also burn more fat during training and experience less hunger throughout the day.

In the 30-minute preworkout window, eat slow carbs in the form of fruit, oatmeal or whole-grain bread along with your protein shake. The meal you have immediately postworkout, however, should consist mainly of fast-digesting carbs such as a plain bagel, baked potato, sports drink (Gatorade, Powerade, etc.) or white bread along with some protein. This will spike levels of the anabolic hormone insulin, which drives carbs into muscle cells to be stored as glycogen and used during your next workout. Insulin also helps amino acids get to muscles to build muscle protein. Normally, you want to keep insulin levels in check for a variety of health reasons, but immediately following a hard training session is one time when an insulin spike is desirable.

6) Drink a shake pre- and post workout

Protein shakes are often considered supplements, but we like to think of them as important meals to be consumed at critical times of day. While your diet should consist mostly of unprocessed, whole foods, a protein shake can sometimes be a better option. One such time is 30 minutes before your workout.

To prepare your muscles for the ensuing training session as well as get a head start on the muscle-recovery process, drink a shake with 20 grams of protein (either whey or a mix of whey and casein) along with about 40 grams of a slower-digesting carbohydrate (see Lesson No. 5). Then, in the 30-minute postworkout window, drink another 20–40 grams of liquid protein (mix in water for convenience) and 60–100 grams of faster-digesting carbs.

7) Eat every 2–3 hours

Eating throughout the day helps you both gain mass and stay lean by ensuring there’s a steady supply of energy and amino acids fueling your muscles. The key is to keep every meal about the same size. If you pig out with a 1,200-calorie lunch, you’ll be less likely to eat 2–3 hours later and could gain the wrong kind of weight, since excess calories are often stored as bodyfat. Aim for 6-8 meals per day.

8) Eat before bedtime

When you sleep, you essentially fast for 7–9 hours. With no food available, the body turns to your muscle fibers for amino acids, which isn’t a good thing for the guy looking to get bigger and leaner. The answer isn’t to sleep less but rather eat the proper foods right before bed.

Slow-digesting proteins and healthy fats are your best bet because they help slow digestion and provide a steady supply of amino acids, thereby minimizing the body’s tendency to break down muscle. Casein, the major protein in milk, is a good option — either from a protein shake or cottage cheese. Before bed every night, consume 30–40 grams of casein protein in a shake (look for micellar casein) or 1 cup of low-fat cottage cheese plus 2–3 tablespoons of flaxseed oil or peanut butter, or 2 ounces of mixed nuts.

9) Add 5–10 grams of BCAAs to your protein shakes

Branched-chain amino acids include isoleucine, leucine and valine. While leucine is the MVP for instigating muscle growth, all three work as a team to provide more energy, strength and muscle size, and even curtail fat gain. BCAAs boost energy levels during workouts because they’re used directly by muscles for energy and they prevent the brain from recognizing fatigue.

Research shows that BCAAs also lower cortisol levels during workouts. Since cortisol is a catabolic hormone that promotes muscle breakdown and inhibits testosterone’s anabolic effects on muscle, reducing it is just one more way to encourage hypertrophy. Go with 5–10 grams in your pre- and post workout shakes. Also consider taking 5–10 grams with your first and last meals of the day.

10) Add 2–5 grams of creatine to your pre- and post-workout shakes

One of the most effective supplements you can purchase is creatine. Many scientists, doctors and nutritionists agree that creatine works very well for most athletes, regardless of age, gender or race. Hundreds of studies show that creatine is not only highly effective but also completely safe. Taking it can help you gain up to 10 pounds of lean muscle and boost your strength in the gym by 10% in just a few weeks with zero side effects.