Best Macros for Weight Loss: What Ratio to Use

Your macro ratio during a calorie deficit determines whether you lose fat and muscle equally, or lose predominantly fat while keeping what you've built. This guide covers the best macros for weight loss based on current evidence — the right protein, carb, and fat split, how to calculate it for your body weight, and how to adjust it when progress stalls.

By the FitCalcHub Editorial Team — Updated July 2026 — 8 min read

Why Macro Ratio Matters During a Calorie Deficit

A calorie deficit causes weight loss regardless of how those calories are distributed — but the macro ratio determines the composition of the weight lost. Research consistently shows that a high-protein deficit diet produces significantly better body composition outcomes than a low-protein deficit of the same calorie total: more fat is lost, and more lean muscle is retained.

Protein preserves muscle during a deficit through two mechanisms. First, it provides the amino acid substrate for muscle protein synthesis, counteracting the increased muscle protein breakdown that occurs under energy restriction. Second, its high thermic effect (20–30% of protein calories are burned during digestion) and satiety effect make the deficit easier to maintain consistently — the single most important factor for long-term fat loss success.

Carbohydrates and fat are both valid energy sources, and neither needs to be eliminated — the optimal split between them depends on personal preference, training volume, and adherence. The non-negotiable is protein.

The Best Macro Ratio for Weight Loss (Evidence-Based)

There is no single universally optimal macro ratio for weight loss — but the research converges on a range that reliably outperforms other approaches for fat loss with lean mass preservation. The best macros for weight loss follow a high-protein, moderate-carb, moderate-fat structure:

Macro	% of daily calories	g/kg body weight	Example: 75 kg, 2,000 kcal
Protein	30–40%	1.8–2.2 g/kg	150 g (600 kcal)
Carbohydrates	30–40%	Fills remainder	185 g (740 kcal)
Fat	25–35%	0.8–1.0 g/kg minimum	73 g (660 kcal)

This structure prioritises protein to protect lean mass, maintains sufficient fat for hormonal health (minimum 0.8–1.0 g/kg), and allocates remaining calories to carbohydrates. Unlike low-carb or low-fat extremes, it does not restrict any macro to the point of impairing training performance or hormonal function. Use the Macro Calculator to generate your complete split in grams based on your specific body weight and calorie target.

Based on: Leidy HJ, Clifton PM, Astrup A, et al. "The role of protein in weight loss and maintenance." Am J Clin Nutr. 2015;101(6):1320S–1329S. PubMed

How to Calculate Your Weight Loss Macros Step by Step

The bodyweight-based method is more precise than percentage ratios alone. Here is how to set your cutting macros from scratch:

Calculate your TDEE. Use the TDEE Calculator to find your maintenance calories. This is the starting point for every macro calculation.
Set your calorie deficit. Subtract 300–500 kcal from your TDEE. A 500 kcal deficit produces approximately 0.5 kg (1 lb) of fat loss per week — a sustainable rate that minimises muscle loss.
Set protein first. Multiply your body weight in kg by 1.8–2.2 g. Multiply by 4 kcal/g to get calories from protein.
Set fat minimum. Multiply body weight by 0.8–1.0 g/kg. Multiply by 9 kcal/g to get calories from fat.
Fill with carbohydrates. Subtract protein and fat calories from your total. Divide the remainder by 4 to get carb grams.

Example — 75 kg, TDEE 2,500 kcal, 500 kcal deficit → 2,000 kcal:
Protein: 75 × 2.0 = 150 g → 600 kcal | Fat: 75 × 0.9 = 68 g → 610 kcal | Carbs: (2,000 − 600 − 610) ÷ 4 = 198 g

For a full guide to what macros are and how they work, see our What Are Macros article. For protein-specific targets, see How Much Protein Per Day.

How to Adjust Your Macro Ratio When Progress Stalls

The most common reason fat loss stalls is that calorie intake has crept above the deficit — not that macros are wrong. Before changing your ratio, verify your deficit is intact by re-calculating your TDEE (body weight changes over time) and reviewing your tracking accuracy.

If energy and training performance are poor

Low carbohydrate intake is the most common driver of training performance decline during a cut. If carbs have fallen below 1.5–2.0 g/kg on training days, consider a small shift: transfer 50–100 kcal from fat to carbohydrates while holding protein constant. This recovers glycogen availability without changing total calories.

If hunger is hard to manage

Increase protein toward the upper end of the range (2.2 g/kg). Protein has the strongest satiety effect of any macro and has a high thermic cost — both properties help control hunger within a deficit without adding net calories.

Common cutting macro mistakes

Setting protein too low — any protein below 1.6 g/kg during a deficit risks meaningful muscle loss
Cutting fat below 0.5 g/kg — disrupts hormone production, particularly testosterone and oestrogen
Not recalculating TDEE as weight drops — maintenance calories fall with body weight; the deficit must be maintained by reducing intake, not assuming fixed targets
Using percentages without anchoring protein in grams first — on very low calorie diets, percentage-based protein targets often fall short of the bodyweight-derived minimum

Frequently Asked Questions

What is the best macro ratio for weight loss?

The best macro ratio for weight loss is approximately 30–40% protein, 30–40% carbohydrates, and 20–30% fat. The most critical variable is absolute protein intake: 1.8–2.2 g per kg of body weight per day, set before allocating carbs and fat. This high-protein structure preserves lean muscle during the calorie deficit and produces better body composition outcomes than low-protein approaches at the same total calories.

How much protein should I eat to lose weight?

Target 1.8–2.2 g of protein per kg of body weight per day. For a 70 kg person, that is 126–154 g daily. This range is supported by multiple meta-analyses as the optimal target for preserving lean mass during a calorie deficit. Protein should be set in grams first — before carbs and fat — because it is the least flexible macro during weight loss.

Should I cut carbs or fat to lose weight?

Both approaches work for weight loss as long as a calorie deficit is maintained. Cutting carbs tends to reduce water weight quickly (from glycogen depletion) and may help with hunger in some individuals. Cutting fat naturally reduces calorie density since fat provides 9 kcal/g. Research comparing low-carb and low-fat diets at matched calories and protein shows no significant difference in long-term fat loss — adherence is the deciding factor, not which macro is reduced.

What are cutting macros?

Cutting macros refer to the macronutrient targets used during a fat loss phase (a "cut") — characterised by a calorie deficit combined with high protein intake. The goal is to lose predominantly fat while preserving lean muscle mass. A typical cutting macro setup: protein 1.8–2.2 g/kg, fat 0.8–1.0 g/kg minimum, carbohydrates filling remaining calories within the deficit calorie target.

How many carbs should I eat per day to lose weight?

Carbohydrate intake for weight loss is determined by what remains after protein and fat minimums are set within your calorie deficit. For a 75 kg person on 2,000 kcal with 150 g protein and 68 g fat, approximately 198 g of carbohydrates remain. This is above low-carb thresholds and supports training performance. There is no evidence that reducing carbs below this level accelerates fat loss once calories and protein are equated.

Do I need to track macros to lose weight?

No — but tracking significantly improves accuracy. Studies show people underestimate calorie intake by 20–40% without tracking. Even tracking for 2–4 weeks to calibrate intuition is useful. If full macro tracking feels unsustainable, tracking protein alone — ensuring you hit your daily gram target — captures most of the benefit, since protein is the variable most strongly associated with body composition outcomes during a deficit.

How often should I adjust my macros for weight loss?

Reassess your calorie and macro targets every 4–6 weeks, or whenever fat loss has stalled for more than 2–3 consecutive weeks. As body weight drops, TDEE decreases — the same macro targets that created a 500 kcal deficit at 85 kg may only create a 200 kcal deficit at 78 kg. Recalculate TDEE at each milestone and adjust calorie intake accordingly, keeping protein in grams constant or slightly increasing it as total calories drop.

Can I lose weight on a high-carb diet?

Yes — provided a calorie deficit is maintained. Body fat is oxidised when total calorie intake is below expenditure, regardless of the macro composition of those calories. High-carb, low-fat diets with adequate protein have shown equivalent fat loss results to low-carb diets in controlled studies at matched calories and protein. The practical advantage of moderating carbs during a cut is primarily that it creates more room for protein within the calorie budget.

This article is part of our complete Nutrition Guide.

Medical Disclaimer: This article is for educational purposes only. Individual nutritional needs vary. Consult a registered dietitian before making significant dietary changes.

Scientific References

Leidy HJ, Clifton PM, Astrup A, et al. "The role of protein in weight loss and maintenance." Am J Clin Nutr. 2015;101(6):1320S–1329S. PubMed ↗
Helms ER, Zinn C, Rowlands DS, Brown SR. "A systematic review of dietary protein during caloric restriction in resistance trained lean athletes." Int J Sport Nutr Exerc Metab. 2014;24(2):127–138. PubMed ↗
Hall KD, Guo J. "Obesity Energetics: Body Weight Regulation and the Effects of Diet Composition." Gastroenterology. 2017;152(7):1718–1727. PubMed ↗