Cutting [2026]: Complete Guide to Losing Fat and Keeping Muscle

Cutting is one of the most misunderstood phases in weight training. Too often, it turns into aggressive caloric restriction, significant muscle loss, and difficult recovery. Result: less mass, less strength, and ultimately a disappointing silhouette.

A well-run cut is the opposite: continuous fat loss, maximum preservation of muscle mass, and progress that doesn't stop.

---

The Biological Reality of Cutting

Caloric deficit: the only mechanism that counts

To lose fat mass, the body must spend more energy than it takes in. That's the caloric deficit. There's no way around this principle: no specific food, no meal timing, no supplement.

That said, the depth of the deficit and the composition of the intake determine what you lose: fat or muscle.

Why an excessive deficit destroys muscle

A high caloric deficit (–1000 kcal or more) sends a starvation signal to the body. In response, it tries to save energy by lowering basal metabolism and breaking down the most energetically costly tissues — including muscle.

This phenomenon is called proteolysis. It's inversely proportional to the quality of protein intake and to muscle stimulation. A moderate deficit, sufficient protein and maintained training minimize it strongly.

---

Calculating Your Caloric Deficit

Step 1: Calculate total energy expenditure (TDEE)

Total energy expenditure is the sum of basal metabolism (energy at rest) and energy spent through activity.

Mifflin-St Jeor formula (basal metabolism):

• ▸Male: 10 × weight (kg) + 6.25 × height (cm) – 5 × age + 5
• ▸Female: 10 × weight (kg) + 6.25 × height (cm) – 5 × age – 161

Activity coefficient:

| Level | Coefficient | |---|---| | Sedentary (desk job, little activity) | × 1.2 | | Lightly active (1-3 sessions/week) | × 1.375 | | Moderately active (3-5 sessions/week) | × 1.55 | | Very active (6-7 sessions/week) | × 1.725 |

Multiply basal metabolism by the matching coefficient. You get your TDEE: the number of calories to consume to maintain your current weight.

Step 2: Apply the deficit

Recommended deficit: –300 to –500 kcal per day.

This deficit produces a loss of 0.3 to 0.5 kg per week — a pace that preserves muscle and stays sustainable for several months.

A –500 kcal deficit over 7 days represents a weekly deficit of 3500 kcal, or about 400-450 g of fat mass lost per week (accounting for water retention and glycogen variations).

Don't aim for more than 0.7-1% of your body weight lost per week. Beyond that, muscle loss accelerates significantly.

---

Macronutrients: the Key to Muscle Preservation

Protein: raise it during a cut, don't lower it

That's the most common mistake: cutting protein at the same time as calories. During a cut, protein needs go up.

Recommendation: 2.0 to 2.4 g of protein per kg of body weight.

This protein surplus vs a mass phase has two roles:

1. Provide the amino acids needed for muscle protein synthesis despite the energy deficit
2. Increase satiety: protein is the most filling macronutrient

Recommended sources: white meat, fish, eggs, cottage cheese, Greek yogurt, legumes, tofu. Protein intake can be topped up with whey if dietary intake falls short.

Carbs: cut them smartly

Carbs are the first target for reduction during a cut, but not to be eliminated. They fuel training sessions and maintain muscle glycogen levels, which directly influence performance and muscle fullness.

Strategy: concentrate carbs around training sessions — before for energy, after for recovery. Reduce carbs on rest days.

Amount: after setting protein, carbs take up 35-50% of the remaining calories.

Fats: don't go too low

Dietary fats play a role in hormone production, including testosterone. Dropping below 0.7 g per kg can compromise the hormonal environment needed to maintain muscle.

Recommended minimum: 0.7 to 1 g of fat per kg of body weight.

---

Training During a Cut

Maintain intensity, not necessarily volume

The classic mistake: moving to light loads and long sets during a cut, convinced it "burns more fat". Wrong on both counts.

The muscle-maintenance signal is load intensity. Your muscles need to keep being exposed to the loads they've adapted to. If you drastically drop the loads, the body has no reason to preserve that muscle.

Recommended strategy:

• ▸Maintain the fundamental exercises and heavy loads
• ▸Moderately reduce volume if recovery is compromised (10-15% maximum)
• ▸6-10 rep sets at high loads preserve muscle better than 15-20 rep light sets

Cardio: complementary tool, not primary

Cardio amplifies the caloric deficit without touching food intake. It's useful, but has limits:

• ▸Excess cardio increases muscle catabolism, especially fasted
• ▸It fatigues the nervous system and compromises recovery between weight training sessions

Recommended format: 2 to 4 weekly sessions of moderate cardio (LISS: Low Intensity Steady State), 30 to 45 minutes at 60-70% of max heart rate. Jogging, cycling, elliptical. Avoid intense HIIT sessions alongside a demanding weight training program.

---

Cutting Duration and Pace

The ideal duration

An effective cut lasts between 8 and 20 weeks, depending on how much fat mass you need to lose. Below 8 weeks, the strain is too high and muscle loss goes up. Beyond 20 weeks of continuous deficit, metabolic adaptation (metabolism slowdown) erodes results.

If you have more than 10 kg of fat to lose, consider splitting the cut into phases separated by maintenance weeks (return to maintenance calories for 2-4 weeks). These maintenance breaks restart the metabolism and make the next phase easier.

Tracking results correctly

The scale alone is a bad indicator during a cut. Weight fluctuates by ±1.5 kg based on hydration, stored carbs and the hormonal cycle. More reliable tracking:

• ▸Weekly average of daily weigh-ins instead of a single reading
• ▸Photos every 2-3 weeks in the same conditions (morning, fasted, same lighting)
• ▸Measurements: waist and hip circumference
• ▸Training performance: if loads drop sharply, the deficit is probably too high

---

The 5 Most Common Cutting Mistakes

1. Deficit too aggressive from the start

Starting at –800 or –1000 kcal starves the body of fuel, collapses performance, and triggers muscle breakdown. The first weeks look promising on the scale (water and glycogen loss), then progress slows and fatigue sets in.

2. Reducing protein

See previous point. In a caloric deficit, raising protein is the single most important decision to preserve muscle.

3. Dropping compound exercises

Some lifters switch to cardio circuits or "sculpting" exercises during a cut. The muscle-maintenance signal comes from strength training with loads. Without that signal, muscle loss accelerates.

4. Neglecting sleep

Cortisol (stress and catabolism hormone) rises with lack of sleep. In a caloric deficit, the body is already slightly stressed. Insufficient sleep worsens the situation and compromises fat loss as much as muscle preservation.

5. Changing plans too often

An effective cut takes time. Results aren't visible week to week, especially if the starting body fat percentage isn't very high. Changing programs or tweaking macros every two weeks prevents you from evaluating what works.

---

Mass Building or Cutting: How to Choose?

If your body fat is above 15-20% (male) or 25-30% (female), a cutting phase first is logical. High body fat reduces insulin sensitivity and the hormonal environment, which slows mass building.

If your body fat is below 12% (male) or 20% (female) and your muscle base is limited, a mass phase is the priority. Cutting only makes sense if it reveals sufficient muscle mass.

---

Nutritional Tracking: Theory vs Practice

Calculating macros is useful. Hitting them every day over several weeks is hard. A few practical tools:

Prep meals in advance: batch cooking on the weekend, portions prepared for the week. Removes tiring food decisions during the week.

Food database: an app that scans barcodes and automatically calculates macros cuts entry time to under 2 minutes per meal.

Flexibility on sources, rigidity on totals: protein, carb and fat sources can vary. Daily totals must stay close to targets.

---

Summary: The Golden Rules of Cutting

1. Moderate deficit: –300 to –500 kcal/day to lose fat without sacrificing muscle
2. High protein: 2.0 to 2.4 g/kg to preserve muscle mass in deficit
3. Maintained strength training: heavy loads and compound exercises, even during a cut
4. Reasonable loss pace: 0.3 to 0.7% of body weight per week
5. Limited duration: 8 to 20 weeks, with breaks if needed
6. Objective tracking: photos + measurements + performance, not just the scale

Cutting is a phase, not a permanent lifestyle. Done well, it reveals the work done during mass-building phases. Done badly, it erases it.