Weight-Loss Levers
A control panel for body composition. Every input below is a lever you actually control. Move one, watch rate of loss, the fat-vs-lean split, time to goal, and a sustainability score react.
Calibrated against a real cut: ~1,400 kcal/day, ~17 h daily fast, ~53 g net carb, → 2.0–2.4 lb/week, bottoming at 160 lb before adherence (not metabolism) ended it at week 3.
Quick Reference — Levers by Leverage
| Lever | What it controls | Leverage | Effort to hold | Your setting |
|---|---|---|---|---|
| Energy deficit | How fast you lose weight at all | Highest | High (willpower) | ~300–500 now; ~750+ later |
| Eating window (TRE) | Caps intake without counting — your proven tool | Highest | Low (a rule) | 16:8, default rule |
| Sleep | Whether the loss is fat or muscle | Highest | Constrained (newborn) | Protect ruthlessly |
| Protein | Muscle retention in the deficit | High | Medium | 150–180 g (you ran 95) |
| Resistance / BJJ | Signals the body to keep muscle | High | Medium | BJJ 2–3× + 1–2 lifts |
| Steps / NEAT | Pads the deficit; weak alone | Moderate | Low | 7–9k (you cut to 5.7k) |
| Carb level / electrolytes | Water weight + how the cut feels | Low (real loss) | Medium | Moderate; salt K⁺/Mg²⁺ |
| Adherence system | Whether any of the above survives week 3 | Decisive | Build once | Weekly weigh-in automation |
The uncomfortable truth from your own data: you don't have a weight-loss problem (you hit 160), you have a drift problem. Drift is beaten by a small permanent change held for years, not a big temporary one held for three weeks.
Lever Lab
Your numbers
The levers
Projection
Model is a transparent estimator, not a measurement. Assumptions and citations are in The Math. Your config saves locally on this device.
The Levers, One by One
1. Energy deficit — the only thing that causes loss
Weight changes with energy balance, not exercise. A deficit of ~3,500 kcal ≈ 1 lb of mostly-fat tissue (a useful approximation; real tissue is ~3,100–3,500 and the rule drifts as you get leaner).
Concrete (you): estimated TDEE ~2,400–2,600. Your 2023 cut ate ~1,400 → a ~1,000–1,200 kcal deficit → ~2.0–2.4 lb/week. Effective, but above the muscle-sparing ceiling.
Gotcha / when not to: deficits >25–30% of TDEE accelerate lean-mass loss and willpower burnout. During the newborn window, run small (300–500 kcal); save the aggressive cut for when you're sleeping.
2. Eating window (TRE) — caps intake without counting
Time-restricted eating compresses the hours you can eat. It works by making a deficit happen passively — there's nothing to log, so it survives chaos. It is not magic beyond the deficit it creates.
Concrete (you): Jan 2023 averaged a 17.1 h fast (16 h+ on 24/31 days). The narrow window is precisely why you hit 1,400 kcal without daily macro tracking. This is your single most sustainable tool.
Gotcha: a wide window (>10 h) plus a big intended deficit means you're back to counting — the thing that broke at week 3. Pick a window and treat it as identity ("I don't eat before noon"), not a daily decision.
3. Sleep — decides whether you lose fat or muscle
Under matched calorie restriction, sleeping 5.5 h vs 8.5 h produced the same weight loss but cut the fraction lost as fat by 55% and raised fat-free (muscle) loss by 60% (Nedeltcheva 2010, mean age 41, mostly men — i.e., you).
Concrete (you): newborn fragmentation is suppressing your HRV and capping sleep. That is the strongest argument against an aggressive cut right now — you'd disproportionately burn muscle and feel terrible.
Gotcha: you cannot out-protein or out-train a severe sleep deficit. If sleep is <6 h, the correct deficit is "barely any."
4. Protein — the muscle-retention floor
For lean, trained people in a deficit, 1.8–2.7 g/kg bodyweight (≈2.3–3.1 g/kg lean mass) maximizes muscle retention (Helms 2014; ISSN position stand). Above ~2.4 g/kg adds little.
Concrete (you): 83 kg → target ~150–225 g/day. Your Jan cut averaged 95 g (~1.15 g/kg) — well under, which is one reason a chunk of the 160-lb low was likely lean tissue.
Gotcha: protein's benefit is real but second-order to the deficit and sleep. It protects the quality of the loss; it doesn't drive the amount.
5. Resistance / BJJ — the "keep this muscle" signal
Resistance training during a deficit tells the body the muscle is needed, shifting loss toward fat. BJJ counts partially (it's intense but not progressive-overload hypertrophy work).
Concrete (you): garage has a heavy bag + pull-up bar; BJJ 2–3×/week is your anchor. BJJ 2–3 + 1–2 short lifts covers the retention signal without adding hours you don't have.
Gotcha: training is for muscle retention, not "burning off" food — your 2023 data showed exercise contributed ~nothing to the actual loss (5.7 min/day avg).
6. Steps / NEAT — pads the deficit, weak solo
Non-exercise activity (walking, fidgeting, standing) is a real but modest contributor — a few hundred kcal/day swing. Useful as a deficit pad, useless as a primary lever.
Concrete (you): you cut steps from ~7,900 to 5,739/day during the 2023 loss and still lost — proof the deficit, not movement, did the work. 7–9k is a fine maintenance band.
Gotcha: don't trade sleep or recovery for step targets during the newborn window.
7. Carb level / electrolytes — water weight + how it feels
Dropping carbs produces a fast 3–5 lb whoosh (glycogen + water), not fat — and reverses the moment carbs return. The real cost is electrolytes: low-carb strips potassium and magnesium and inverts the Na:K ratio, which manufactures fatigue.
Concrete (you): Jan 2023 ran ~53 g net carb (moderate, not keto). Micronutrient logs showed potassium 64% RDA, magnesium 85%, plus low B-complex and choline — a fatigue tax stacked on newborn fatigue.
Gotcha: carb level is a comfort/scale-noise lever, not a fat-loss lever. If you go low-carb, deliberately salt potassium/magnesium/B-complex or the cut feels like illness.
8. Adherence system — the decisive meta-lever
None of the above matters past the point you stop doing it. Your 2023 cut didn't fail metabolically — logging died Feb 20 and the deficit quietly vanished, producing a 3-year regain to 183–191.
Concrete (you): the fix is structural, not motivational: one passive weekly weigh-in trend, a rule-based eating window, and an automated nudge — not the app streak counter that already failed once.
Gotcha: the failure point is week 3. Design for that specific cliff instead of assuming willpower scales.
Common Mistakes & Anti-Patterns
- Running a sprint, not a ratchet. Aggressive 3-week cuts followed by regain (your exact sawtooth). A small permanent change beats a big temporary one.
- Cutting hard on no sleep. The fastest way to lose muscle and quit. Match deficit size to sleep quality.
- Treating exercise as the deficit engine. It's the muscle-retention signal; the kitchen sets the deficit.
- Tracking everything until you crash. High-burden logging is the documented failure mode. Prefer rules (window, protein floor) over daily math.
- Confusing the carb whoosh with fat loss. The first 3–5 lb is water and comes back; judge by a 7-day trend, not day-to-day.
- Under-eating protein. 95 g at 83 kg sheds muscle. Floor it at ~1.8 g/kg.
- Weighing daily and reacting. Noise. Use a weekly average; that's the real signal.
Three Protocols (load them in the lab)
Newborn-safe ratchet now
The only one to run during fragmented sleep. Bank the habit, not the loss.
- 16:8 window as a fixed rule
- ~300–500 kcal deficit (≈0.5 lb/wk)
- Protein 150 g+
- BJJ 2–3× + 1 short lift
- Weekly weigh-in only
Post-sleep cut later
When sleep consolidates (~7.5 h). Faster but muscle-sparing.
- ~700–900 kcal deficit (~1 lb/wk, ≤1% BW)
- Protein 170–180 g
- BJJ 3 + resistance 2
- 8 h eating window
- K⁺/Mg²⁺/B-complex floor
Your 2023 cut reference
What you actually did — the calibration baseline. Effective but fragile.
- ~1,400 kcal, ~1,000+ deficit
- ~17 h fast, ~53 g net carb
- Protein only 95 g
- ~2.0–2.4 lb/wk (a bit fast)
- Broke at week 3 (adherence)
The Math (so you can trust the dials)
Maintenance (TDEE) = Mifflin-St Jeor BMR × activity factor.
BMR = 10·kg + 6.25·cm − 5·age + 5 (male). Defaults assume 178 cm, age 45; edit weight + activity in the lab.
Rate = deficit × 7 ÷ 3,500 lb/week. The 3,500 kcal/lb rule is an approximation that overstates loss slightly as you lean out.
Fat-vs-lean split starts at ~78% fat and is adjusted by protein (g/kg), training frequency, sleep, and deficit aggressiveness, then clamped to 35–92%. The sleep term is anchored to Nedeltcheva 2010 (5.5 h vs 8.5 h: −55% fat fraction, +60% lean loss). It is a directional estimate, not DEXA.
Sustainability score rewards moderate deficit, adequate sleep, adequate protein, and a narrow eating window (your proven tool); it penalizes aggressive deficits and short sleep. It encodes the lesson that the binding constraint is adherence, not knowledge.
Sources (primary, verified 2026-06-20):
- Nedeltcheva AV et al. Insufficient Sleep Undermines Dietary Efforts to Reduce Adiposity. Ann Intern Med 2010;153:435–441.
- Helms ER et al. A Systematic Review of Dietary Protein During Caloric Restriction in Resistance-Trained Lean Athletes. IJSNEM 2014.
- Jäger R et al. ISSN Position Stand: Protein and Exercise. JISSN 2017 (1.4–2.0 g/kg general; 2.3–3.1 g/kg deficit retention).
- Helms ER et al. Evidence-based recommendations for natural bodybuilding contest prep. JISSN 2014 (0.5–1%/wk for muscle retention).