How do I cut (lose fat) without losing muscle?

Eat in a moderate deficit so you lose about 0.5 to 1 percent of your body weight a week. Keep protein high and keep lifting with the same intensity. Research on lean lifters dieting for competition recommends exactly this pace to keep as much muscle as possible. Fat should stay at about 15 to 30 percent of calories, with the rest from carbs.

1. Set a moderate deficit. Start about 10 to 20 percent below maintenance, aiming for 0.5 to 1 percent of body weight a week.
2. Raise your protein. Aim for at least 1.6 to 2.2 grams per kilogram of body weight. Leaner lifters may benefit from more.
3. Keep lifting heavy. Keep your main lifts and weights. Cutting volume a little is fine, but keep the intensity.
4. Track and adjust. Log your food and weekly average weight. Adjust calories when progress stalls for two to three weeks.
5. Know when to stop. When you reach your goal, or after a few months, raise calories back to maintenance for a while.

The recommendations behind this

A 2014 review of the research on natural bodybuilders preparing for competition recommended:

• Losing about 0.5 to 1 percent of body weight per week to keep muscle.
• Eating plenty of protein, more than general guidelines, during a diet.
• Keeping fat at about 15 to 30 percent of calories, with the rest from carbs.
• Spreading protein over three to six meals a day.

Those recommendations come from very lean athletes, so most people can use the less extreme end.

Keep an eye on the right numbers

• Weekly average weight: the main guide for adjusting calories.
• Strength on main lifts: if it holds, you’re likely keeping muscle.
• Waist measurement: a useful check alongside the scale.
• How you feel: constant exhaustion or obsession with food is a sign to ease off.

If dieting starts to affect your mood, sleep or relationship with food, stop and talk to a professional.