Cutting Macros Guide
Protein protects muscle. Fat supports hormones. Carbs fuel performance. Here's exactly how to set each one for a successful cut.
Protein: The Non-Negotiable Macro
If you only optimize one macro during a cut, make it protein. Multiple meta-analyses confirm that high protein intake during caloric restriction significantly attenuates lean mass loss compared to moderate protein intakes.
The current evidence-based target is 2.0–2.4g of protein per kg of lean body mass per day. Some studies (Helms et al., 2014) suggest leaner athletes benefit from going even higher — up to 3.1g/kg — as body fat drops below 10%.
Why LBM, Not Total Bodyweight?
Fat tissue doesn't need protein for maintenance. Using total body weight inflates your protein needs if you have higher body fat. LBM-based calculations are more accurate for athletes across all body composition levels.
Calculate your LBM: Body Weight × (1 − Body Fat% ÷ 100)
Your protein target: LBM in kg × 2.2
Best Protein Sources for Cutting
| Food | Protein/100g | Calories/100g | Protein Efficiency |
|---|---|---|---|
| Chicken breast (cooked) | 31g | 165 cal | ★★★★★ |
| Turkey breast | 29g | 135 cal | ★★★★★ |
| Egg whites (liquid) | 11g | 52 cal | ★★★★★ |
| White fish (cod, tilapia) | 23g | 105 cal | ★★★★★ |
| Greek yogurt (0%) | 10g | 59 cal | ★★★★☆ |
| Cottage cheese (low-fat) | 11g | 85 cal | ★★★★☆ |
| Whey protein (1 scoop) | 25g | 120 cal | ★★★★★ |
| Shrimp | 24g | 99 cal | ★★★★★ |
| Tuna (canned in water) | 25g | 116 cal | ★★★★★ |
| Lean beef (96% lean) | 22g | 152 cal | ★★★★☆ |
PlateLens tracks all macros automatically from a photo
Snap your meal — protein, carbs, fat, and total calories calculated instantly. No manual logging.
Fat: Set the Floor, Don't Go Below It
Dietary fat is often the first thing people slash on a cut. This is a mistake. Fat serves functions that carbohydrates cannot:
- Testosterone synthesis — fat is a precursor to steroid hormones. Drop fat too low and testosterone tanks, directly increasing muscle catabolism.
- Fat-soluble vitamin absorption — vitamins A, D, E, and K require dietary fat for absorption.
- Omega-3 status — EPA and DHA are critical for inflammation management during heavy training.
- Satiety — fat slows gastric emptying, which helps manage hunger on a restricted diet.
The minimum for most male athletes is 0.8g of fat per kg of bodyweight. Women typically need slightly higher minimums (1.0g/kg) due to hormonal sensitivity.
Don't go below these minimums. Ever. The performance and hormonal consequences aren't worth the extra calorie headroom.
Best Fat Sources for Cutting
Prioritize unsaturated fats: olive oil, avocado, almonds, salmon, mackerel. These provide omega-3s and oleic acid alongside their calories. Avoid processed seed oils — they're high-calorie with poor micronutrient profiles.
Carbs: Your Performance and Flex Macro
After protein and fat are set, carbs fill the remaining calories. This means carbs drop as your deficit increases — which is fine. Carbs are not essential in the way protein and fat are, but they are your primary performance fuel.
The big carb lever on a cut is timing. On training days, eat more carbs (peri-workout). On rest days, reduce carbs slightly and increase fat slightly. This is the basis of carb cycling.
Carb Sources That Work on a Cut
Prioritize high-volume, high-fiber carbs: white rice, oats, sweet potato, fruit, rice cakes. Avoid foods that are simultaneously high in carbs AND high in fat (pasta with cream sauce, pizza) — these are calorie bombs that eat your macro budget.
Practical Example: Setting Macros for a Cut
Example athlete: 85kg male, 18% body fat, moderately active
LBM = 85 × 0.82 = 69.7kg
Protein: 69.7 × 2.2 = 153g (612 cal)
Fat: 85 × 0.8 = 68g (612 cal)
Daily cutting target: 2,250 cal
Remaining: 2,250 − 612 − 612 = 1,026 cal
Carbs: 1,026 ÷ 4 = 256g
Macro Tracking: Why ±5% Isn't "Close Enough"
A lot of people think being "roughly" on their macros is fine. The math disagrees. If you're 5% over on both protein and carbs every day:
Extra protein: 153 × 1.05 = 161g → +32 extra calories
Extra carbs: 256 × 1.05 = 269g → +52 extra calories
Daily surplus from "rough" tracking: 84 extra calories
Weekly: 588 extra calories — nearly a full meal
After 12 weeks: ~7,000 extra calories — equivalent to about 0.9kg of fat you didn't burn because your tracking was "roughly" right.
Know Your Exact Macros at Every Meal
PlateLens breaks down protein, carbs, and fat from a single photo. You set the targets — it does the tracking. Available on iOS and Android.