Resistance training during caloric maintenance can support muscle growth while burning stored fat, especially in individuals with higher body fat.
Original: I Tested 3 Muscle Building Diets, Only 1 Was Worth It
Evidence supports that muscle gain and fat loss can occur together under maintenance calories, but only when sufficient body fat is present.
Quick Answer
Only the lean bulk diet was worth it for Dayton's goal of building muscle without excessive fat gain. The fast bulk produced the most muscle (1.8 lbs in 30 days) but also tripled fat gain compared to the lean bulk. The maingain diet surprisingly built 1.1 lbs of muscle while reducing fat, but the lean bulk—250-calorie surplus, 1–2 lb monthly weight gain—delivered the optimal balance of muscle growth and minimal fat accumulation for someone planning to cut to 12% body fat later.
Claims (10)
1. Even when you’re eating less to lose fat, your body can still build muscle if you lift weights and have enough fat stored.
2. Eating more carbs gives you more energy to lift heavier and work out longer.
3. Your body can use fat you already have as fuel to build new muscle.
4. If you exercise hard but don’t eat extra calories, your body can use stored fat to build muscle.
5. New people who lift weights and eat a lot can get really strong and muscular without getting fat.
6. If you eat too much to gain muscle, you might get so fat that you never bother to lose it.
7. If you’re already skinny and lean, you can’t build muscle well unless you eat more.
8. You don’t need a lot of protein to build muscle—just 0.7 grams per pound of body weight is enough to grow as much muscle as possible.
9. New lifters can gain muscle fast with lots of food, but experienced lifters mostly gain fat when they eat a lot.
10. If you’re getting stronger lifting the same weights, you’re probably gaining muscle—even if the scale doesn’t move.
Key Takeaways
- •Problem: People want to gain muscle but often end up gaining too much fat when they eat too many calories.
- •Core methods: Lean bulk, fast bulk, maingain.
- •How methods work: Lean bulk adds 250 calories above maintenance to slowly build muscle with little fat; fast bulk adds 500 calories to maximize energy for workouts and muscle growth but causes more fat gain; maingain eats at maintenance calories and uses stored body fat to fuel muscle growth.
- •Expected outcomes: Lean bulk gained 1.35 lbs muscle with minimal fat; fast bulk gained 1.8 lbs muscle but 3x more fat; maingain gained 1.1 lbs muscle and lost fat.
- •Implementation timeframe: Results were measured every 30 days over a 90-day period, with muscle gains visible within 4–6 weeks and fat changes detectable via measurements.
Overview
Dayton, a 17% body fat individual who had recently cut from 33%, aimed to build muscle permanently without regaining fat. Three diets were tested over 90 days: maingain (maintenance calories), fast bulk (500-calorie surplus), and lean bulk (250-calorie surplus). All diets used identical resistance training (5 days/week with dumbbells, bench, pull-up bar) and protein intake (≥100g/day). The solution previewed was identifying which caloric approach maximized muscle gain while minimizing fat accumulation, using objective measurements (DXA, ultrasound, strength logs) to determine the most sustainable method.
Key Terms
How to Apply
- 1.Calculate your maintenance calories by multiplying your body weight in pounds by 13–16 based on activity level; for Dayton, this was 2300 kcal/day.
- 2.For lean bulk: Add 250 calories to your maintenance (e.g., 2550 kcal/day), prioritize carbs for energy, consume at least 100g protein daily, and train 5 days/week with compound movements using dumbbells, bench, and pull-up bar.
- 3.For fast bulk: Add 500 calories to your maintenance (e.g., 2800 kcal/day), increase carbohydrate intake to fuel intense workouts, maintain 100g+ protein, and train 5 days/week with progressive overload.
- 4.For maingain: Eat at your calculated maintenance calories (e.g., 2300 kcal/day), consume 100g+ protein, train 5 days/week with consistent resistance exercises, and monitor weight to stay stable.
- 5.Track strength progress weekly using a workout app (e.g., Built With Science+), focusing on 6–12 rep range lifts like pull-ups, bench presses, and dumbbell rows.
- 6.Measure body composition every 30 days using DXA scan, skinfold calipers, ultrasound, and waist circumference to track muscle and fat changes.
- 7.Adjust diet based on results: If gaining >2 lbs/month, reduce surplus; if gaining <0.5 lbs/month, increase surplus slightly; if losing fat while gaining strength, continue maingain.
Following these steps, you can expect to gain 1–2 lbs of muscle per month with lean bulk and minimal fat gain, 2–3 lbs of muscle per month with fast bulk but significant fat gain, or 1 lb of muscle per month with maingain and potential fat loss if you have sufficient body fat stores.
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Claims (10)
1. Even when you’re eating less to lose fat, your body can still build muscle if you lift weights and have enough fat stored.
2. Eating more carbs gives you more energy to lift heavier and work out longer.
3. Your body can use fat you already have as fuel to build new muscle.
4. If you exercise hard but don’t eat extra calories, your body can use stored fat to build muscle.
5. New people who lift weights and eat a lot can get really strong and muscular without getting fat.
6. If you eat too much to gain muscle, you might get so fat that you never bother to lose it.
7. If you’re already skinny and lean, you can’t build muscle well unless you eat more.
8. You don’t need a lot of protein to build muscle—just 0.7 grams per pound of body weight is enough to grow as much muscle as possible.
9. New lifters can gain muscle fast with lots of food, but experienced lifters mostly gain fat when they eat a lot.
10. If you’re getting stronger lifting the same weights, you’re probably gaining muscle—even if the scale doesn’t move.
Related Content
Claims (10)
A caloric maintenance state combined with resistance training can result in simultaneous fat loss and muscle gain by mobilizing endogenous fat stores to support muscle protein synthesis.
Protein intake at 0.7 grams per pound of body weight is sufficient to maximize muscle protein synthesis in non-elite, non-lean individuals undergoing resistance training.
In individuals with elevated body fat stores, resistance training during a caloric deficit can sustain muscle hypertrophy while promoting net fat loss.
The efficiency of muscle gain during a caloric surplus is significantly higher in untrained individuals compared to trained individuals, with the latter accumulating proportionally more adipose tissue under the same surplus conditions.
Endogenous adipose tissue serves as a metabolic substrate that can support muscle protein synthesis during periods of caloric restriction or maintenance.