Tip: Mass Gain 101

Here's the smart way to adjust your diet and your training for your next bulking phase.

Not for Fat Guys

These guidelines are for those who are relatively lean (around 10% body fat) and whose main goal is to build muscle. Stick to these guidelines for 10-16 weeks until you reach 15%.

For weight training, you'll need high volume work mostly in the 6-12 rep range. As for nutrition, you'll need:

  • A surplus of calories
  • Adequate protein to maximize muscle protein synthesis
  • Sufficient fat intake to optimize hormonal levels
  • High carbs to support the high volume training

Let's break it down.

Total Calories

You need to eat a surplus of calories. Eat enough to gain 0.25 to 0.5% of your bodyweight per week. That will equate to roughly 200-500 calories a day over maintenance.

A good rule of thumb when starting out is to multiply your bodyweight in pounds by 16 and eat that many calories per day. But that's just a rough guide. Many will need to eat 17 to 20 times their weight. If you begin at 16 and you're not gaining weight, bump it up to 17 and then re-assess. Keep adjusting until you're gaining weight at the desired rate.

The body is an infinitely complex system with countless feedback loops. Your needs will continue to fluctuate based on numerous factors. As you progress through your mass phase your calorie needs will adjust. Continue to monitor scale weight and adjust based on that. Not gaining quickly enough? Increase by 250-500 calories a day (lower end for smaller guys and higher end for bigger guys).

Now you can move on to refining your macronutrient needs.


Muscle protein synthesis (MPS) is arguably the most important physiological factor when it comes to building muscle. Eating protein stimulates MPS. Muscle growth can only occur if MPS exceeds muscle protein breakdown.

So it's imperative you eat enough protein to max out your MPS across the course of a day. Interestingly, research indicates there's an amount of protein which achieves this and eating more doesn't have any additional benefit, at least for muscle gains.

To build muscle, anything in the range of 1.6 to 2.2 grams per kg of lean mass is sufficient. But since not everyone has access to a DEXA machine, let's keep it simple and shoot for 2g/kg of bodyweight. (In American, that's close to 1 gram of protein per pound of body weight. One kilogram is 2.2 pounds.)

Split this intake into 4-6 meals each day based on your preference and schedule.


Eating dietary fat is important for regular hormonal function, especially testosterone production. It should never be eliminated from the diet. It's not so much an "optimal" fat intake, but a minimum for normal hormonal function. Science tells us that fat intake should be between 20-30% of total calories to optimize testosterone production.

With that said, once the 0.35g/lbs. (0.8g/kg) threshold has been crossed, no significant benefit to hormones is apparent when in a caloric surplus. Above and beyond the amount of fat needed for hormonal function, structural, and chemical processes, it simply becomes a fuel source, like carbs. It's wise to not exceed the 0.35g/lbs. threshold when bulking.


Once protein and fats are set, then carbs make up the rest of your total calories. Carbs, like fats, have a positive impact on hormones. They're also the dominant source of energy for the central nervous systems (CNS) and high intensity activities, like lifting weights. They help to fuel grueling training and aid recovery.

Approximately 80% of your weight training is fuelled by glycogen stores (stored carbs). Low glycogen will impair your training and recovery. Eating sufficient carbs allows you to train at a higher intensity, with higher volumes, and recover quicker. Carbs have anti-catabolic and anabolic effects and are a huge advantage to hard-training individuals, especially those aiming to build muscle.

Your carbohydrate needs are based on your activity levels. Given you should be training with high volumes during a mass gain phase, your carb needs will be high. A recent scientific review recommended carb intakes between 4-7g/kg for strength athletes. Most recreational, hard training guys will fall at the lower end of this range. For most, 4-5g/kg is ample. (So, a 170 pound guy in mass phase would need roughly 308 to 385 grams of carbs per day.)

How to Track Progress During a Mass Phase

Aim to gain 0.25 to 0.5% of bodyweight per week. In real world math, the 170 pound guy should be trying to gain roughly 1 or 2 pounds every two weeks, but don't let the decimal points and percentages make you crazy. Lots of things can throw off scale weight, so just keep this as a general guideline.

When progress stalls, increase calories by 250 to 500 per day – lower end for lighter and/or fatter individuals and the higher end for bigger and/or leaner folks.

Adjust based on scale weight with the predominance of additional calories coming from carbs.

Your strength in the 6-12 rep range should be increasing consistently.

Tom MacCormick is a former skinny kid who was told he was too small to make it as a rugby player. Since then, he has added over 40 pounds to his frame and helped hundreds of clients build muscle and burn fat. Follow on Instagram