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Cutting Diet Macros: The Complete Guide to Shredding Fat

A cutting phase is a strategic period of fat loss designed to strip body fat while preserving as much lean muscle mass as possible. Unlike casual dieting, a proper cut demands precise macronutrient targets, structured deficit management, and planned recovery strategies. This guide covers everything from setting your cutting macros to refeed protocols, sample meal plans, and knowing when to end your cut.

What Is a Cutting Phase?

A cutting phase is a deliberate period of caloric restriction where the primary goal is reducing body fat while maintaining lean muscle mass. It differs from general weight loss in several critical ways: protein intake is elevated well above standard recommendations, resistance training remains intense, and the approach is time-bound rather than indefinite.

Cutting phases are commonly used by bodybuilders preparing for competitions, athletes making weight classes, and recreational lifters who want to reveal the muscle they have built during a bulking phase. The principles apply equally whether you are aiming for stage-ready conditioning or simply want to look lean at the beach. For general weight loss approaches, see our macros for weight loss guide.

The key distinction between a successful cut and a failed one comes down to macronutrient precision. Lose weight too fast without enough protein, and you sacrifice hard-earned muscle. Cut too slowly with suboptimal macros, and you spend months spinning your wheels. This guide gives you the exact framework to get it right.

The Optimal Cutting Macro Split

The most effective macro ratio for a cutting phase is:

This split prioritizes protein for muscle preservation while keeping carbohydrates high enough to fuel resistance training and fat sufficient for hormone production. Research published in the Journal of the International Society of Sports Nutrition consistently supports high-protein approaches during caloric restriction for lean athletes.

Cutting Macro Targets by Calorie Level

Here are specific gram targets for cutting diets at various calorie levels. These use the 40/30/30 split and can be adjusted based on individual needs. For the complete calculation process, see our how to calculate macros guide.

Setting Your Calorie Deficit for Cutting

The size of your calorie deficit should be determined by your current body fat percentage, not by a one-size-fits-all number. Leaner individuals carry less fat and are at greater risk of muscle loss from aggressive deficits. The National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) supports gradual approaches for sustainable body composition changes.

Rate of Weight Loss by Body Fat Percentage

A more precise approach is to target a percentage of your body weight per week. This scales the deficit automatically based on your size and leanness:

For a step-by-step breakdown of calculating your TDEE and setting a deficit, see our TDEE calculation guide.

Visual: Deficit Size by Body Fat Level

Protein Requirements During a Cut

Protein is the single most important macronutrient during a cutting phase. Research consistently shows that higher protein intake during caloric restriction preserves significantly more lean muscle mass. A landmark study by Helms et al. (2014) in the Journal of the International Society of Sports Nutrition found that resistance-trained athletes in a deficit should consume 1.0 to 1.4 grams of protein per pound of body weight.

The leaner you are, the more protein you need. This is because leaner individuals have less body fat available for energy, so the body is more likely to catabolize muscle tissue during a deficit. Elevating protein intake counteracts this by maintaining a high amino acid availability for muscle protein synthesis. For a deeper dive into protein requirements, read our protein intake guide.

Why Higher Protein Works During a Cut

• Muscle protein synthesis: A sustained supply of amino acids keeps muscle-building pathways active even in a deficit, as reviewed by Examine.com's protein research.
• Thermic effect of food: Protein costs 20-30% of its calories just to digest. On a 200g protein diet, that is 160-240 extra calories burned daily.
• Satiety: Protein is the most filling macronutrient. High protein meals reduce ghrelin (hunger hormone) and increase peptide YY (fullness hormone).
• Reduced muscle breakdown: Adequate leucine from protein sources directly inhibits muscle protein breakdown pathways.
• Better body composition: Studies show that high-protein dieters lose more fat and retain more muscle than low-protein dieters at the same calorie level.

Best Protein Sources for Cutting

For more protein-rich food options, see our best foods for hitting your macros guide.

Refeed Day Protocol

Refeed days are structured, planned increases in calorie intake, primarily from carbohydrates, that temporarily reverse some of the hormonal downsides of dieting. They are not cheat days. Every macro is still tracked. The primary purpose is to boost leptin levels, replenish muscle glycogen, and provide a psychological break from the deficit.

On a refeed day, extra calories come almost entirely from carbohydrates. Carbs have the strongest impact on leptin — the hormone that signals energy availability to your brain. Fat and protein have minimal effects on leptin. Good refeed carb sources include rice, potatoes, oats, bread, pasta, fruit, and lower-fat sweets. Keep fat low on refeed days to allow maximum carb intake without excessive calorie surplus.

Refeed Day Example: 180 lb Male at 16% Body Fat

Diet Break vs Refeed: When to Use Each

Diet breaks and refeeds serve similar purposes but differ in duration and application. Understanding when to use each tool is critical for long-term cutting success.

Research published in the International Journal of Obesity found that subjects who alternated between 2-week dieting blocks and 2-week maintenance breaks lost significantly more fat and experienced less metabolic adaptation than those who dieted continuously for the same total duration. For guidance on maintenance eating, see our maintenance macros guide.

Metabolic Adaptation During a Cut

Metabolic adaptation is the single biggest obstacle to long-term cutting success. When you maintain a caloric deficit for extended periods, your body fights back by reducing energy expenditure through multiple mechanisms:

• Reduced BMR: Your body becomes more metabolically efficient, burning 5-15% fewer calories than predicted by your weight alone.
• Decreased NEAT: Non-exercise activity thermogenesis drops subconsciously. You fidget less, stand less, and move less without realizing it — sometimes burning 200-400 fewer calories per day.
• Hormonal shifts: Leptin drops (increasing hunger), ghrelin rises (increasing appetite), thyroid output decreases (lowering metabolic rate), and cortisol increases (promoting water retention and fat storage).
• Reduced TEF: You are eating less food, so less energy is spent on digestion.

How to Combat Metabolic Adaptation

• Use diet breaks: 1-2 weeks at maintenance every 8-12 weeks resets hormonal markers and reduces adaptive thermogenesis.
• Keep protein high: High protein preserves metabolically active muscle tissue, keeping your BMR higher.
• Maintain training intensity: Do not reduce weight or volume during a cut. Your body needs the stimulus to justify keeping muscle tissue.
• Monitor NEAT: Track daily steps and consciously maintain your movement levels. Aim for 8,000-10,000 steps daily regardless of how deep into your cut you are.
• Avoid overly aggressive deficits: Moderate deficits cause less metabolic adaptation than extreme ones, as supported by the American College of Sports Medicine (ACSM).

Preserving Muscle During a Cut: Training Recommendations

Your training during a cut should focus on maintaining strength and muscle stimulation, not on burning calories. Here are the evidence-based principles:

The cardinal rule of cutting training: if you want to keep muscle, train as if you are trying to build it. The biggest mistake people make during a cut is switching to light weights, high reps, and excessive cardio — a recipe for muscle loss. For training-specific macro guidance, see our macro calculator for athletes.

Cardio Strategy During a Cut

Sample Cutting Meal Plan: 1,800 Calories

This plan targets approximately 180g protein, 135g carbs, and 60g fat — suitable for a 180 lb individual doing a moderate cut.

Sample Cutting Meal Plan: 2,200 Calories

This plan targets approximately 220g protein, 165g carbs, and 73g fat — suitable for a 200-220 lb individual on a moderate cut.

For more meal ideas and food choices, explore our meal prep for macros guide.

Sample Cutting Meal Plan: 1,500 Calories (Aggressive Female Cut)

This plan targets approximately 150g protein, 110g carbs, and 50g fat — suitable for a 130-150 lb female doing an aggressive cut.

For women-specific macro guidance, see our macro calculator for women.

Supplements for Cutting

While supplements are never required, certain evidence-based options can support your cut:

The NIH Office of Dietary Supplements provides detailed guidance on vitamin and mineral supplementation.

When to End a Cut

Knowing when to stop cutting is just as important as knowing how to start. Pushing a cut too far leads to hormonal dysfunction, muscle loss, binge eating, and metabolic damage. Here are the key signals that it is time to end your cut:

• You have reached your target body fat: For most men, 10-12% body fat reveals clear muscle definition. For most women, 18-22% provides a lean, athletic appearance. Going below these levels is typically only necessary for competition.
• Strength has dropped significantly: A decrease of 15-20% or more on your main compound lifts indicates that you are losing muscle, not just fat.
• You have been cutting for 16+ weeks continuously: Even with diet breaks, extended cuts become increasingly counterproductive as metabolic adaptation compounds.
• Persistent fatigue and mood disruption: Chronic low energy, irritability, poor sleep, and loss of motivation are signs your body needs a recovery phase.
• Hormonal symptoms: Loss of menstrual cycle in women, significant libido decrease in both sexes, or chronic cold hands and feet indicate hormonal suppression from excessive dieting.
• Calories are already very low: If you are a man eating under 1,500 calories or a woman under 1,200 calories and still not losing, it is time for a diet break and reverse diet rather than cutting calories further.

Signs You Should Stop Your Cut Immediately

Transitioning From a Cut to Maintenance

The post-cut transition is where many people fail. Jumping straight from cutting calories back to pre-diet eating causes rapid fat regain due to suppressed metabolic rate and elevated hunger hormones. The solution is a structured reverse diet.

Reverse Diet Protocol

• Week 1-2: Increase calories by 100-150 per day, primarily from carbohydrates. Keep protein at cutting levels (1.0-1.2 g/lb).
• Week 3-4: Add another 100-150 calories. Begin to moderate protein slightly downward (0.8-1.0 g/lb) as the deficit closes.
• Week 5-6: Continue adding 100-150 calories per week. Fat can increase moderately. Monitor body weight — some gain of 2-4 lbs from water and glycogen is normal and expected.
• Week 7-8: You should be approaching your new maintenance level. Stabilize here for at least 4 weeks before considering another cut or a bulk.

Reverse Diet Example: 180 lb Male

For the complete reverse dieting protocol, see our dedicated reverse dieting explained guide. If you are transitioning into a muscle-building phase, our macros for muscle gain guide has you covered.

How to Calculate Your Cutting Macros Step by Step

Step 1: Calculate Your TDEE

Use the Mifflin-St Jeor equation or our free macro calculator to find your Total Daily Energy Expenditure. See our TDEE calculation guide for details.

Step 2: Set Your Deficit

Subtract 400-750 calories based on your body fat percentage (see tables above).

Step 3: Set Protein

Multiply your body weight by 1.0-1.2 to get protein grams. If significantly overweight, use goal weight.

Step 4: Set Fat

Multiply your body weight by 0.3-0.4 to get fat grams. Never go below 0.25g/lb.

Step 5: Calculate Carbs

Subtract protein calories and fat calories from total calories. Divide remainder by 4.

Calculation Example: 200 lb Male at 22% Body Fat

Common Cutting Mistakes

• Cutting calories too aggressively too early. Start with the smallest effective deficit. You can always reduce more later, but you cannot undo the metabolic damage from going too hard too fast.
• Dropping protein when calories get low. As calories decrease, protein should stay the same or increase, not decrease. Cut from carbs and fat first.
• Using excessive cardio instead of managing diet. Two hours of daily cardio to compensate for a poor diet leads to muscle loss, injury, and burnout. The deficit should come primarily from food.
• Switching to high-rep, light weight training. This removes the primary stimulus your body needs to retain muscle during a deficit.
• Ignoring refeed days and diet breaks. These are not optional luxuries. They are essential tools that make your cut more effective, not less.
• Extending the cut indefinitely. More is not always better. Prolonged dieting beyond 16-20 weeks without breaks leads to diminishing returns and increasing harm.
• Weighing yourself daily and overreacting. Weight fluctuates 2-5 lbs daily from water, sodium, and food volume. Track weekly averages instead.
• Neglecting sleep. Poor sleep increases cortisol, reduces testosterone, impairs recovery, and increases hunger. Aim for 7-9 hours.

For more common nutrition misconceptions, see our macro myths debunked article.

Tracking Your Cut

Monitor these metrics to ensure your cut is progressing optimally. For app recommendations, see our macro tracking apps guide.

Frequently Asked Questions

Calculate My Cutting Macros →

Research & References

This guide is based on peer-reviewed research and established sports nutrition guidelines:

• Helms et al. (2014) — A systematic review of dietary protein during caloric restriction in resistance trained lean athletes — JISSN
• Jager et al. (2017) — ISSN Position Stand: Protein and Exercise — Journal of the International Society of Sports Nutrition
• Trexler et al. (2014) — Metabolic adaptation to weight loss: implications for the athlete — JISSN
• Intermittent energy restriction improves weight loss efficiency — Int J Obesity (2017)
• NIDDK — Weight Management Resources — National Institutes of Health
• Dietary Guidelines for Americans 2020-2025 — U.S. Department of Agriculture
• Harvard T.H. Chan School of Public Health — Protein
• Examine.com — Optimal Protein Intake Guide
• NIH Office of Dietary Supplements — Vitamin D
• American College of Sports Medicine — Exercise and Weight Management

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