Is Keto Good for Cutting? What the 2024 ISSN Position Stand Says

Keto remains one of the most polarising topics in cutting nutrition. Some of the people you trust will tell you it's a magic switch for fat loss; others will tell you it's an outdated fad with worse outcomes than balanced macros. The International Society of Sports Nutrition tried to settle the question in 2024 with a position stand — Leaf, Rothschild, Sims, Aragon, Antonio and twelve other authors who span the field — synthesising the available evidence specifically for athletes and active populations.

What the 2024 position stand actually concluded

The headline finding from Leaf et al. (2024) in the Journal of the International Society of Sports Nutrition is more nuanced than either keto camp wants:

• Fat oxidation rises significantly on a ketogenic diet — about 1.5 g/min during exercise, up from ~0.5–1.0 g/min on a balanced diet
• This does not translate to better performance. Aerobic performance is largely neutral or impaired on keto, especially at intensities above 70% VO₂max — the body's ability to use carbohydrate for high-effort work is compromised
• Strength training outcomes are equivocal — strength gains are similar to non-keto diets, but lean mass changes are more variable
• Fat mass loss is greater on keto — but so is fat-free mass loss, and both are confounded by typically larger caloric deficits and lower protein intakes in keto trial conditions
• When protein and calories are matched, the body composition gap narrows substantially

That last point is the one that does the most work in answering the cutting question. Most of the apparent advantage keto shows in body composition trials evaporates once you control for the things that actually drive fat loss — calorie deficit and adequate protein.

Where keto looks defensible — and where it doesn't

Keto's strongest case is in physically active but not high-intensity populations. Coleman et al. (2021), in their Journal of the International Society of Sports Nutrition systematic review, pooled 13 studies on physically active people running ketogenic diets:

• Average total body mass loss: −2.7 kg vs control
• Average fat mass loss: −2.3 kg vs control
• Average fat-free mass loss: −0.3 kg (minimal)

That looks favourable until you read the methodological notes: trials varied in how strictly ketosis was verified, training modality varied widely, and several relied on bioelectrical impedance (BIA) for body composition — which is notoriously noisy. The signal is real but the confidence intervals are wide.

For a cutting lifter specifically, the trade-offs sharpen:

• High-intensity strength training depends on glycolytic fuel; keto compromises that exact system
• Volume tolerance drops — you can do less hard work per session before fatigue overwhelms recovery
• Glycogen-dependent compound lifts (squats, deadlifts, anything in the 6–12 rep range) tend to feel meaningfully worse on keto, particularly in the first 4–6 weeks
• Protein intake often drops because keto-friendly protein sources are calorie-dense (eggs, fatty meats, cheese), so hitting a 2 g/kg target inside a deficit is harder to engineer

The longer-term picture — Lei 2022

The standard counter to "keto helps you lose more fat" is: yes, in the short term, then it converges. Lei et al. (2022) in Frontiers in Nutrition meta-analysed 33 RCTs comparing low-carb to low-fat diets in overweight and obese adults over 6–23 months:

• Low-carb beat low-fat by 1.33 kg of weight loss over 6 months — small but statistically significant
• Triglycerides dropped more on low-carb; LDL cholesterol dropped more on low-fat
• At 24 months, all differences in weight and metabolic markers converged — both diets performed equally

The clinical implication is clear: the diet you can sustain wins. The "keto loses more weight" finding holds during the period when adherence is high; once adherence equalises (i.e., people get bored of the rules), the gap closes. For a 12-week cut you might capture some of that early advantage. For an extended cutting and maintenance cycle running into the next year, it doesn't matter which side of the macro split you live on.

What about strength and performance?

The ISSN 2024 stand is precise here: strength gains on keto are roughly equivalent to non-keto diets in trained populations, particularly for tasks below the lactate threshold. Where keto starts to struggle is the high-intensity, glycolytic-demand portion of training — the kind of work that produces hypertrophy in the 6–15 rep range. Lifters on keto often report being able to maintain 1RM strength while losing the ability to hit their usual rep counts at submaximal loads.

If strength preservation is your goal, both keto and balanced macros work. If hypertrophy preservation is the goal, balanced macros at adequate protein remain the more defensible default for most lifters most of the time.

When keto might genuinely fit

Despite the above, keto isn't categorically wrong for cutting — it just isn't the default. Cases where it makes more sense:

• Endurance lifestyle with low-to-moderate intensity training as the primary modality
• Genuine appetite struggles on balanced macros, particularly carb-driven cravings that derail adherence
• Insulin resistance or metabolic syndrome — the population in which Lei 2022 found the favourable triglyceride and HDL changes
• Personal preference and adherence — you've tried keto, you find it sustainable, and your protein and total calories are dialled in

If none of those apply, balanced macros at 1.6–2.2 g/kg of protein and a 15–20% deficit is the lower-risk play.

A practical decision framework

1. Are you hitting a 12+ week extended cut? → Adherence trumps macro composition. Pick whichever diet you can sustain at the right protein.
2. Is your training hypertrophy-focused, mostly 6–15 rep range, glycogen-dependent? → Default to balanced macros. Keto compromises the exact stimulus you're after.
3. Do you have insulin resistance or metabolic markers that need attention? → Keto becomes more defensible (Lei 2022 lipid changes are real)
4. Have you tried keto and found it sustainable? → Continue, but track protein scrupulously — the failure mode is under-eating protein

The ISSN 2024 position is essentially "diet philosophy doesn't override the basics." Calorie deficit and adequate protein still drive cutting outcomes. Macro split is a fine-tuning lever, not the engine.

Key Takeaways

• ISSN 2024 position stand: keto raises fat oxidation but doesn't improve performance and shows no body composition advantage once protein and calories are matched (Leaf 2024)
• Active populations on keto lose ~2.7 kg total and ~2.3 kg fat with minimal lean tissue loss (Coleman 2021), but trial quality is mixed
• Long-term (24 months), keto and balanced diets produce equivalent weight loss and metabolic outcomes (Lei 2022)
• Keto compromises high-intensity glycolytic work — strength gains hold, but hypertrophy in the 6–15 rep range tends to suffer
• Default for cutting lifters: balanced macros, 1.6–2.2 g/kg protein, 15–20% deficit
• Keto becomes defensible for endurance training, persistent appetite struggles, insulin resistance, or established personal preference

Sources

1. Leaf A et al. (2024). International Society of Sports Nutrition Position Stand: Ketogenic Diets. Journal of the International Society of Sports Nutrition. PMC
2. Coleman JL, Carrigan CT, Margolis LM (2021). Body composition changes in physically active individuals consuming ketogenic diets: a systematic review. Journal of the International Society of Sports Nutrition. PMC
3. Lei L et al. (2022). Effects of low-carbohydrate diets versus low-fat diets on metabolic risk factors in overweight and obese adults: A meta-analysis of randomized controlled trials. Frontiers in Nutrition. PMC