Nutrition & Body Composition

The answer

~1,600 kcal/day

Typical adult range: 1,200 – 2,200 kcal/day

For a bw_70kg, 170 cm, 30-year-old adult, it's around 1,500–1,650 calories at rest depending on sex. The formula: 10 × weight (kg) + 6.25 × height (cm) − 5 × age, then +5 for men or −161 for women. This is your floor — every step, lift, and bike ride adds to it.

The answer

Mifflin-St Jeor

Lands within 10% of measured value in more cases than Harris-Benedict, Owen, or WHO/FAO/UNU

When a fitness app or calorie tracker asks for your weight, height, age, and sex to set a daily target, it is almost certainly running Mifflin-St Jeor underneath. This review is why — it beat the three other commonly-used formulas at predicting how many calories a typical adult burns at rest, and the advantage held in obese adults too, where older equations like Harris-Benedict tend to drift. If a tool you use defaults to Harris-Benedict, switch to Mifflin if the option exists.

The answer

Mifflin-St Jeor is most accurate

Mifflin: 82% within ±10% · Livingston: 79% · Accuracy lower in obese

Across 7 RMR prediction equations tested against indirect calorimetry in 337 adults, the Mifflin-St Jeor equation was the most accurate (82% of estimates within ±10% of measured RMR). Livingston was a close second at 79%. All equations performed worse in obese participants than in non-obese, regardless of which equation was used — meaning prediction error is partly a function of body size, not just the equation choice. The takeaway: Mifflin-St Jeor is the right default for general adults, but expect more error at higher body fat levels.

The answer

Equation accuracy depends on demographics

HB 57.5% · Mifflin 56.4% · WHO/FAO/UNU 55.2% · Owen under-predicts · Subgroup variance is large

Across 362 healthy adults, three RMR equations performed similarly at the population level: Harris-Benedict (57.5%), Mifflin (56.4%), and WHO/FAO/UNU (55.2%) all hit within ±10% of measured RMR for roughly the same fraction of participants. Owen consistently under-predicted. The actually-important finding: accuracy varies a lot by demographic subgroup — sex, BMI, age, and race/ethnicity all modify which equation fits best. The takeaway: the population-level equation choice matters less than recognizing that any equation will under- or over-shoot for specific subgroups.

The answer

Mifflin-St Jeor still best, but limited

Mifflin: 50.4% · HB: 36.8% · BIA: 36.1% within ±10% of IC

In 133 overweight and obese adults, Mifflin-St Jeor was the most accurate of three commonly-used BMR estimation methods, with 50.4% of estimates falling within ±10% of measured RMR (vs Harris-Benedict 36.8%, BIA 36.1%). Notably, all three methods over-predicted BMR by 100–200 kcal/day on average. The takeaway: Mifflin remains the right default even for higher-BMI populations, but expect substantial individual-level variation — only about half of estimates land within ±10% of true RMR, even with the best equation.

The answer

79.5 % within ±5% of DEXA

Lin concordance: 0.89 (men) · 0.86 (women) vs DEXA

For most adults, a tape measure around your neck and waist gets you within five percentage points of what a DEXA scan would show. That's good enough to track change over months — better than calipers, far cheaper than imaging. The errors are roughly balanced (about 9 percent of people get underestimated, 11 percent overestimated), so the method has no systematic bias.

The answer

Comparable

A measuring tape, used correctly, sits in roughly the same accuracy ballpark as calipers and basic bioimpedance for estimating body fat — at a fraction of the cost and with no operator-skill bottleneck. That's the reasoning behind the Navy method this app uses. Source is a 1998 conference abstract; full-text details (exact error bands per method) are not publicly accessible.

The answer

Bad at small changes

ADP: +2.1% body fat · DoD equation: +0.3% body fat

Tape-measure equations are fine for a single snapshot, but they're not sensitive enough to track small body-composition shifts in lean young men over months. If you're using the Navy method to monitor progress, expect it to lag and to under-register fat-mass changes that more direct methods like a Bod Pod or DEXA would catch. Small sample (21 men) — treat as a single signal, not a definitive verdict.

The answer

3-comp + TBW is most accurate

Siri 3-comp: ≤0.4% diff · Simpler methods: ±4.0–10.7% total error

When body-composition methods are tested against a 4-compartment reference (the Heymsfield gold standard), the 3-compartment hydrostatic weighing approach with total body water correction is the most accurate (mean differences ≤0.4% Fat, correlations >0.997). Simpler methods — including DEXA in some cases, skinfolds, and other field tools — carry substantially greater error (±4.0% to ±10.7% Fat). For app users tracking body-fat changes, this reinforces the importance of using a single consistent method over time rather than comparing absolute readings across different measurement approaches.

The answer

Field methods are population-level tools

Equivalence-tested · Lab vs field comparisons · Individual-level error substantial

Field body-fat measurement methods (skinfolds, BIA, circumference) work reasonably well for tracking populations but carry substantial individual-level prediction error compared to DEXA or other gold-standard lab methods. The practical implication for the app: don't cross-reference body-fat numbers from different measurement methods as if they're directly comparable. Track changes within the same method over time, and treat absolute numbers as estimates rather than precise readings.

The answer

1.6 g/kg/day

Most studies land between 1.0 – 2.2 g/kg

For someone at 70 kg, that's roughly 112 g of protein a day. Beginners often benefit from the higher end of the range; trained lifters typically plateau closer to the lower end. Going above 2.2 won't add more muscle.

The answer

1.6 vs 1.2 g/kg/day

Younger (<65): ≥1.6 g/kg · Older (≥65): 1.2–1.59 g/kg

For a 60 kg adult under 65, that's ~96 g protein daily. The same person at 70+ may see the same lean-mass benefit from ~80 g. Reinforces the Morton plateau and clarifies the requirement scales down with age.

The answer

30 g/meal (≥60 yr)

Older (≥60): ≥30 g/meal threshold · Younger (<30): no discrete threshold

For adults over 60, spread protein across 3–4 balanced meals instead of loading dinner. Breakfast is especially impactful after the overnight fast. For under-30s, total daily intake matters more than per-meal distribution. The MPS response lasts ~2–2.5 hours per meal, so spacing meals avoids long anabolic gaps.

The answer

~3 g leucine/meal (older + isolated)

Strongest support: adults >60 with whey/casein · Weakest: under-30s with mixed meals

About half the trials (16 of 29) supported the threshold. The hypothesis holds best when an older adult drinks a whey or casein shake — at that point, the 3 g leucine number matters. For a younger adult eating chicken and rice, total protein quantity outweighs the leucine number. Don't chase the 3 g target in mixed-food meals.

The answer

Yes, with the right setup

Author recommendation: 2.6 – 3.5 g/kg of fat-free mass per day, 3+ resistance sessions/week, prioritised sleep

If you are already trained, recomp is still on the table — but the lever is high protein anchored to your lean mass, not your bodyweight. For a bw_70kg lifter at ~20% body fat (about 56 kg FFM), that is roughly 145 – 195 g of protein a day, paired with progressive resistance training at least 3 times a week. Deep, sustained deficits (contest-prep territory) make recomp much harder; moderate intake with strong training is the safer bet.

The answer

~1 kg lean mass gained (lifters)

Men: +0.8 kg FFM, −8.9 kg fat. Women: +0.9 kg FFM, −6.4 kg fat. Non-exercisers lost 1.7 – 2.8 kg of lean mass.

In a 5-month, ~500 kcal/day cut with 1.5 g/kg protein, the people who lifted held onto — and slightly grew — their lean mass while losing fat. The people who only did cardio, or no exercise, lost more lean tissue along with the weight. The signal is consistent across sexes, but the trial was observational, so other lifestyle differences between groups could be doing some of the work.

The answer

Same 3 levers

Higher protein · resistance training (with volume in trained lifters) · moderate caloric restriction

The newer literature reinforces the old recipe. If you want to lose fat without losing muscle, anchor on protein, lift with enough volume for your training age, and don't take the deficit deeper than you need to. The review is a useful pointer to recent primary trials, not a definitive intake number on its own.

The answer

Maybe — sex matters

Women on rising volume: ~+1 kg lean mass. Men averaged ~−2.8 kg lean mass loss across studies.

If you are a trained female athlete cutting on ≥2 g/kg/FFM protein, ramping training volume looks protective and may even nudge you into a small lean-mass gain. If you are a trained male athlete, even high volume and high protein typically won't fully prevent some lean-mass loss in a sustained deficit — expect to lose a bit and aim to minimise it rather than recomp through it.

The answer

2.4 g/kg/day

High protein: +1.2 kg lean, −4.8 kg fat. Low protein (1.2 g/kg): +0.1 kg lean, −3.5 kg fat.

On a deep cut with hard training, doubling protein from 1.2 to 2.4 g/kg/day turned a "barely held on to muscle" outcome into a clear lean-mass gain plus more fat lost. For a bw_70kg adult, that's ~170 g of protein a day. Caveat: the regimen was 4 weeks of 6 sessions/week with intervals — not a long-term lifestyle test.

The answer

−3.8% body fat (lifting + deficit)

Lifting alone: −1.6% body fat, +0.7 kg lean. Lifting + deficit: −3.8% fat, −5.3 kg fat mass, lean preserved.

If you are overweight and want to drop fat, the most effective package in the data is lifting plus a moderate caloric deficit. Lifting alone helps. Dieting alone helps too, but typically costs you lean mass. The combination protects what muscle you have while cutting fat about twice as fast.

The answer

Moderate mixed training

Top-ranked overall: moderate mixed > moderate resistance > low-intensity resistance, all combined with a caloric deficit

For pure fat-loss speed, push aerobic intensity. For a recomp goal — keep muscle, lose fat — a moderate-intensity mix of resistance and cardio inside a deficit ranks highest. Resistance-leaning programs preserve lean mass better than aerobic-leaning ones, so build the week around lifting and add cardio as a deficit lever.

The answer

Lifts win for lean mass

AT and CT lost ~1 kg more fat than RT alone. RT alone preserved FFM best; CT did not statistically differ from RT or AT on FFM.

If your priority is keeping muscle, lifting alone protects fat-free mass best. If your priority is losing absolute kilograms of fat, aerobic or combined wins by about 1 kg. The trade-off is real — combining the two gets you most of the way on both, but the lean-mass advantage of pure lifting gets diluted when you stack aerobic on top.

The answer

~16 weeks detraining still retains nuclei

Animal data: ~42% vs 21% cross-sectional area gain in re-loaded vs naive muscle. Human regrowth-acceleration evidence is suggestive but not conclusive.

If you trained seriously before, the cellular machinery you built is probably still there after months off — that's the biology behind "muscle memory." Returning to lifting after a layoff or pregnancy, you should regain muscle faster than the first time around. The animal evidence for that acceleration is strong; the human evidence is consistent but still small.

The answer

Nuclei stay

Fibers shrank to 23% of post-overload size; myonuclear count was statistically unchanged. Recent human work (Pérez-Castillo 2025) extends the finding to ~16 weeks of detraining.

When you train and grow a muscle, you add nuclei to each fiber, and this study showed those nuclei do not leave when the muscle later wastes — at least in mice. The cellular machinery that drives growth is still in place when you come back to training. The result is animal-only by design; human data so far is consistent with it but covers shorter detraining windows.

The answer

Only fasted or high-volume

Of 19 acute-feeding trials: 13 showed no benefit, 6 showed a benefit

If you eat a normal meal a few hours before lifting, pre-workout carbs are mostly optional. They start to matter when you train fasted (early morning, no breakfast) or run very high-volume sessions — think 10+ sets per muscle group. The endurance-style "fuel every workout with carbs" rule isn't supported for strength training.

The answer

No benefit

Pooled effect was effectively zero (SMD 0.17, not statistically significant)

For trained endurance athletes, deliberately training with low carb availability did not improve performance over standard high-carb training. The trade-off was real: peak-interval intensity suffered. If you race or train hard, fuel the hard sessions. If you want to experiment with train-low, keep it to easy sessions and don't expect a performance edge.

The answer

Yes — small but real

Roughly twice the effect (SMD 0.38) in sessions over 45 minutes

Carbs before lifting give you a modest edge on total work performed — most of the benefit shows up in longer sessions (over 45 minutes) and when you train fasted. For a quick 30-minute strength session after a normal meal, you can skip the pre-workout carbs. For a 60-minute high-volume day, or an early-morning fasted lift, eating something carby beforehand is the safer bet. As a preprint, treat the exact numbers as provisional.

The answer

−19% CHD events (SFA → PUFA swap)

About 10% lower CHD risk per 5% of energy shifted from SFA to PUFA · CI: 0.70 – 0.95

On RobustHealth, swapping a chunk of your saturated fat — butter, fatty meat, full-fat dairy — for polyunsaturated sources like nuts, seeds, fish, and seed oils is the move with the cleanest randomized-trial backing for heart events. The 19% number is the total package effect over multi-year trials; you won't see anything in your bloods at one week. And the evidence is specifically about the swap, not about cutting saturated fat while replacing those calories with carbs or sugar — that's a separate question.

The answer

−28% CVD mortality (per 5%E SFA → PUFA)

SFA → PUFA: 28% ↓ CVD mortality · MUFA: smaller effect · Carbs: neutral for CVD · Sugar/refined starch: increases events

The headline isn't "eat less saturated fat" — it's "what you eat instead matters more than the cut itself." Swapping a slice of saturated-fat energy for polyunsaturated fat (seed oils, nuts, oily fish) is the substitution with the cleanest mortality signal. Swapping it for white bread, sugar, or refined carbs cancels the gain and may make things worse. That's why the app tracks saturated and polyunsaturated fat as separate macros — and why "low fat" labels can be misleading.

The answer

−21% cardiovascular events

Pooled RR 0.79 (CI 0.66–0.93, 11 RCTs) · No effect on CV mortality, all-cause mortality, MI, or stroke individually · SFA → PUFA/MUFA also improved fasting glucose, HbA1c, and insulin resistance

Cutting saturated fat looks like it lowers your chance of a major cardiovascular event over years of follow-up, but it doesn't clearly extend your life — the trials don't show a mortality benefit. The metabolic upside — better glucose control and insulin sensitivity — comes specifically when you replace the saturated fat with polyunsaturated or monounsaturated sources, not when you just cut total fat. Most of the underlying cohort evidence is methodologically weak; the cleaner randomized signal is the cardiovascular-event one.

The answer

Yes, but often modest and reversible

AT in 27/33 studies · ~30–100 kcal/day in most · Smaller in higher-quality studies · Attenuates during maintenance

The directional finding is robust: most weight-loss studies do find a modest reduction in energy expenditure beyond what lean-mass loss alone explains. But the authors explicitly hedge on magnitude — when higher-quality methods are used, AT values shrink, and in some cases disappear entirely. The effect also doesn't appear to be permanent: it attenuates during weight-maintenance phases and is undetectable 6–24 months after bariatric weight loss. The takeaway: weight loss does have a metabolic cost, but it's smaller and more reversible than the popular "metabolic damage" narrative implies.

The answer

No evidence does not support harm

BMI: 13/18 null · Fat mass: 15/20 null · Lean mass: 0/18 decrease · Metabolic rate: 12/14 null

The evidence reviewed here doesn't support the popular "weight cycling damages your metabolism" claim. Across 23 studies, the dominant finding for body weight, body composition, and metabolic rate was no significant association with cycling. That doesn't mean cycling is risk-free in every population (psychological, eating behavior, and cardiovascular outcomes are studied separately), but the specific worry that repeated dieting will permanently lower your metabolism or destroy lean mass is not supported by the evidence the authors reviewed.

The answer

Multiple adaptations compound

REE↓ beyond lean-mass loss · Thyroid↓ · Leptin↓ · Ghrelin↑ · Effects more pronounced in lean populations

For lean and athletic populations specifically, sustained caloric restriction triggers a coordinated set of adaptations — reduced resting expenditure, falling thyroid hormones, falling leptin (the satiety signal), and rising ghrelin (the hunger signal) — that collectively make further loss harder and regain easier. The authors' practical implication is that periodic maintenance breaks may attenuate these adaptations, though they're honest that individual variability is substantial and the specific timeframes are heuristics rather than physiological thresholds.

The answer

25% higher 24-h MPS

EVEN ~30 g/meal vs SKEW 11/16/63 g · FSR 0.075 vs 0.056 %/h (p=0.003) · n=8

When the same ~90 g of daily protein was split evenly across three meals instead of dumped into dinner, the body built measurably more muscle protein over 24 hours. The trial was small (8 people), so treat the exact 25% figure as a directional signal rather than a precise prescription — but it lines up with the broader meal-distribution literature. The practical move: don't leave breakfast and lunch starved of protein and back-load it all at dinner.

The answer

25–30 g/meal

Threshold floor: ~20 g/meal (response blunts in elderly below this) · Same per-meal target applies to young and older adults

About 25–30 g of high-quality protein per meal — three times a day — is the dose this review proposes as the operational target. The threshold matters more in older adults: below ~20 g a meal, the elderly muscle-protein-synthesis response gets blunted; younger adults tolerate smaller meals better. Rather than chasing a higher daily RDA, the practical move is making sure each meal clears the ~25 g bar.

The answer

~30 g/meal (≥60 yr)

Older (>60): ≥2.8 g leucine / ~30 g protein per meal to trigger MPS · Younger (<30): no discrete threshold, MPS scales linearly with per-meal protein

For an adult over 60, each main meal needs roughly 30 g of high-quality protein (~2.8 g leucine) to switch on muscle protein synthesis — fall below that bar and the meal's MPS contribution stalls. For a younger adult, the math is more forgiving: MPS scales smoothly with whatever protein you eat, so a smaller meal can be made up at the next one. As anabolic resistance sets in with age, the strategy shifts from "hit the daily total" toward "make every meal clear the threshold."

The answer

Sometimes depends on conditions

RT + evidence-based nutrition foundational · Sleep, hormones, measurement limitations also matter

Trained individuals can recomposition under specific conditions: structured progressive resistance training combined with adequate protein and an appropriate calorie balance. Non-training variables — sleep quality and hormonal context — also moderate the outcome, as do real measurement limitations in body composition assessment (DXA, BIA, skinfolds all have noise that can mask small simultaneous changes). The honest framing is that recomposition is possible but harder than pure cutting or pure bulking, and works best for those with higher initial body fat or returning to training.

The answer

Sometimes magnitude unknown

Specific optimal surplus is unknown · Trained-lean populations benefit more · Novices/higher-BF can gain at maintenance or below

The honest answer: it depends on who you are. Trained lean populations likely need a surplus to maximize the RATE of muscle gain. Novices, returning lifters, and people with higher starting body fat can build muscle at maintenance or even slightly below. The specific magnitude of surplus needed isn't validated by current literature — the authors are explicit that "the specific energy surplus required to facilitate muscle hypertrophy is unknown." Practical implication for recomposition eligibility: the exact thresholds the app uses are reasonable defaults, not derived from a single anchor study.

The answer

2.3–3.1 g/kg LBM (contest-prep)

Contest-prep: 2.3–3.1 g/kg LBM · General RT (Morton): 1.6–2.2 g/kg bodyweight · Different populations

For trained, lean populations attempting recomposition — particularly those targeting low body fat — the Helms contest-prep protein floor (2.3–3.1 g/kg of lean body mass per day) is the relevant upper anchor. For more general recomposition scenarios (higher starting body fat, less aggressive deficit), the Morton 2018 general-RT floor (1.6–2.2 g/kg of bodyweight) applies. The denominators differ (LBM vs bodyweight) — comparing the numbers directly is misleading.

The answer

0.5–1 %/week

0.5–1%/week loss · 2.3–3.1 g/kg LBM protein · 15–30% fat · Population: natural bodybuilders

For lean, resistance-trained populations seeking further fat loss, the authors recommend a moderate deficit producing roughly 0.5–1% body weight loss per week. The protein floor they establish — 2.3–3.1 g/kg of lean body mass per day — is notably higher than general-population recommendations and is specifically tuned to muscle preservation under caloric restriction. Important context: this is a contest-prep population, where the goal is extremely low body fat with full muscle preservation. The recommendations may be more aggressive than typical fat-loss users need, but they anchor the upper-bound protein and the lower-bound deficit-rate that the app applies during fat-loss phases.

The answer

~6–8 weeks heuristic, not threshold

REE↓ · Thyroid↓ · Leptin↓ · Ghrelin↑ · Specific timeframes are heuristics, not thresholds

For lean and athletic populations, sustained caloric restriction triggers a coordinated set of adaptations that tilt the system against further loss. The authors' practical guidance is to use periodic maintenance breaks to interrupt these adaptations. The "6–8 week" timeframe cited in app prompts is the paper's discussion-level heuristic — useful as a default, but not a hard physiological threshold.

The answer

For maximum gains yes

Position paper · Bodybuilding/physique focus · Surplus required only to maximize hypertrophy rate

You can build muscle without a surplus — particularly if you're newer to lifting, returning after a break, or carrying enough body fat to fuel new growth from existing stores. But to maximize the rate of muscle gain, the authors argue an energy surplus is required. The paper's practical scope is bodybuilders and physique athletes pursuing peak hypertrophy; the surplus magnitude and macronutrient composition recommendations are tuned to that population.

The answer

0.25–0.5 %/week of bodyweight

0.25–0.5%/week gain · Protein 1.6–2.2 g/kg bodyweight · Per-meal 0.40–0.55 g/kg evenly distributed

For natural off-season muscle gain, the authors recommend a slow, controlled rate of weight gain — 0.25–0.5% of bodyweight per week. That's roughly 0.5–1.0 lb/week for a 200 lb lifter — slower than the popular "bulk" heuristics, deliberately so to limit fat accumulation. Protein at 1.6–2.2 g/kg of bodyweight (note: bodyweight, not lean mass — different from contest-prep recommendations), spread evenly across meals at 0.40–0.55 g/kg per serving. Faster gain rates were associated with disproportionate fat gain in the underlying literature.

The answer

~1.6 g/kg/day

Plateau ~1.6 g/kg/day · Older adults benefit less · Trained individuals benefit more

Protein supplementation drives muscle gain from resistance training, but the dose-response saturates at about 1.6 g/kg of bodyweight per day. Above that, more protein doesn't add more fat-free mass. Two moderators worth surfacing: protein supplementation is less effective with age, and more effective with training experience. The 1.6 g/kg figure is the most-cited quantitative anchor in modern protein-and-RT recommendations.

The answer

More is better with diminishing returns

+0.023 effect size per additional weekly set · No clean plateau identified in abstract

Weekly training volume drives hypertrophy in a graded, dose-response fashion: every additional set per muscle per week added a small but measurable increment to hypertrophy effect size (0.023 per set). The widely-used "10–20 sets per muscle per week" prescription is a practical heuristic that combines this dose-response with real-world recovery considerations — the abstract itself documents continued benefit across the studied range without specifying a clean ceiling.

The answer

150 min/wk moderate (or 75 vigorous)

150–300 min/wk moderate · 75–150 min/wk vigorous · ≥2 days/wk strengthening · Limit sedentary time

The headline number from the WHO 2020 guidelines: 150 minutes of moderate-intensity aerobic activity per week is the floor for "meets minimum recommendations" — or 75 minutes of vigorous activity, or an equivalent mix. Plus muscle-strengthening on at least two days per week. Sedentary time should be limited. The 300-minute upper threshold reflects additional benefit at higher doses without a clearly diminishing return for general-health outcomes. The app's 150-minute weekly aerobic floor is anchored to this guideline.

The answer

150 + 2-3 min cardio + RT days/wk

≥150 min/wk moderate aerobic · 2–3 days/wk resistance · ≥2 days/wk flexibility

The ACSM's combined-modality prescription for general fitness: at least 150 minutes per week of moderate-intensity cardio (or 75 vigorous), resistance training on 2–3 days per week covering each major muscle group, and flexibility work on at least 2 days per week. This is the most-cited general-population prescription in sports medicine and the basis for the foundational-health modality in the app.

The answer

1.0–1.2 g/kg/day minimum (more if active)

General: 1.0–1.2 g/kg · Active: ≥1.2 g/kg · With disease: 1.2–1.5 g/kg · Per-meal: ~25–30 g

For adults over 65, the PROT-AGE Study Group recommends at least 1.0–1.2 g/kg of bodyweight per day — notably higher than the general adult RDA (0.8 g/kg). Active older adults should aim for at least 1.2 g/kg, and those with acute or chronic disease should aim for 1.2–1.5 g/kg. The widely-cited per-meal floor (~25–30 g of high-quality protein) helps operationalize the daily target across meals. The reason for the elevated requirement: older muscle responds less robustly to dietary protein ("anabolic resistance"), so a higher dose is needed to drive the same anabolic response.

The answer

Whole foods limit added sugar/sodium/sat-fat

Added sugar <10% cal · Sodium <2,300 mg/day · Saturated fat <10% cal · Life-stage stratified

The federal DGA recommendations the commentary explains: emphasize nutrient-dense whole foods (vegetables, fruits, whole grains, lean proteins, low-fat dairy); limit added sugars to less than 10% of total calories; limit sodium to less than 2,300 mg/day; limit saturated fat to less than 10% of calories. The 2020–2025 edition was the first to provide explicit guidance from birth through older adulthood. The app's maintenance-calorie / whole-food framing aligns with these consensus recommendations.

The answer

Heavy low-rep wins for strength

Volume-equated · Hypertrophy: similar across protocols · Strength: powerlifting-style superior

When total volume was matched, both heavy/low-rep (7 × 3RM, 3-min rest) and moderate/higher-rep (3 × 10RM, 90s rest) produced similar muscle hypertrophy in trained men. But maximal strength was significantly higher in the heavy/low-rep group. The practical implication: hypertrophy is forgiving of rep-range choice when total volume matches, but maximal strength specifically requires heavy loads, low reps, and longer rest periods. Train for what you're trying to optimize.

The answer

Adequate protein + carbs context-dependent

Strength mode: Morton 1.6–2.2 g/kg bodyweight protein · Contest-prep edge: Helms 2.3–3.1 g/kg LBM · Carbs to fuel sessions

For most strength-training users, the general-RT protein floor (1.6–2.2 g/kg of bodyweight, per Morton 2018) is the relevant anchor — the Helms contest-prep recommendations (2.3–3.1 g/kg of lean body mass) apply specifically to the lean, contest-prep edge case. The cross-cutting principle that applies to both: carbohydrate intake should be sufficient to fuel hard sessions. Strength work is glycogen-dependent — under-fuelling impairs performance and recovery.

The answer

Heavy + multi-set + long rest failure not required

2–5 min rest · Multiple sets > single sets · Heavy + light load combo · Failure not necessary

The Suchomel synthesis identifies several programming principles for maximal strength: rest 2–5 minutes between sets, do multiple sets per exercise, combine heavy and light loads across a training cycle, and — notably — training to failure is NOT necessary for maximum strength gains. For weaker athletes, strength should come before power-specific training. The takeaway: strength prescription is more about consistent progressive overload across heavy-loaded multi-set work than about pushing every set to failure.

The answer

5–10 + 1.2–2.0 g/kg carb + g/kg protein

Carbs: 5–10 g/kg/day scaled to load · Protein: 1.2–2.0 g/kg/day · Energy availability matched to training

The tri-organizational position-stand recommendations: carbohydrate intake of approximately 5–10 g/kg/day, scaled to training volume and intensity — lower on rest/easy days, upper on hard or long sessions. Protein at 1.2–2.0 g/kg/day to support training adaptation. The defining operational principle for endurance: carbohydrate intake tracks training load, rather than sitting at a fixed daily target. This is what distinguishes endurance from other strategy modes in the app.

The answer

Periodize carbs to session demand

Train-low · Train-high · LCHF · Periodized carb diet · Events >30 min to ~24 hr

The contemporary best practice the paper identifies: a "periodized carbohydrate diet" — matching daily and weekly carbohydrate intake to session-specific demands. High carbs for hard sessions and races, lower carbs for easy/recovery days. The "train low" approach (deliberately training with reduced carbs) is a more advanced strategy that may enhance mitochondrial adaptations but should be used selectively, not universally. The chronic LCHF approach is a separate dietary path with its own trade-offs around high-intensity capacity. Strategy choice depends on the event distance and training phase.

The answer

Macro · Meso · Micro aligned to training

Macro: training phase · Meso: weekly structure · Micro: session/meal level

The Stellingwerff framework periodizes nutrition at three timescales: macro (training-phase level — base/build/taper differ in fuelling priorities), meso (weekly hard/easy day patterns), and micro (session-by-session and meal-by-meal carb availability). The central principle the framework operationalizes: nutrition shouldn't sit at a fixed daily target — it should track training prescription. The endurance strategy's training-load-tracked calorie modulation is the application of this framework.