Food · lesson 11 of 11
Eating for your goal
Fat loss vs maintenance vs muscle gain — calculating a deficit or surplus, recomposition, protein, refeeds, and adjusting over time.
8 min read · reviewed October 2026
Everything in this track converges here: turning the principles into a plan aimed at a specific goal. Whether you want to lose fat, hold steady, or build muscle, the structure is the same — set an energy direction, anchor protein, fill the rest with quality food, then adjust based on real-world results.
This lesson walks through each goal, how to set the numbers, and — most importantly — how to keep adjusting as your body responds.
The three goals, side by side
Eat below maintenance so the body draws on fat stores. Keep the deficit moderate (~10–20%, often 300–500 kcal/day), push protein high to protect muscle, and lean on fiber and volume to stay full. Aim for roughly 0.5–1% of body weight lost per week — faster tends to cost muscle and adherence.
Eat at maintenance to hold your weight. Underrated as a goal: maintenance is where you practise the habits that make any future loss or gain stick, and a deliberate maintenance phase after a diet helps the body and appetite hormones recalibrate.
Eat modestly above maintenance (often ~5–15%, ~150–350 kcal/day) to fuel growth, paired with progressive resistance training and ample protein. A small surplus builds muscle with minimal fat; a large 'dirty bulk' mostly adds fat you'll later have to cut.
Calculating your deficit or surplus
Estimate your maintenance calories (your TDEE), then subtract for fat loss or add for muscle gain. The estimate is just a starting point — you confirm and adjust it by watching the scale and the mirror over a few weeks.
How it works →
Start by estimating maintenance (TDEE) — either from an equation (BMR via Mifflin-St Jeor × an activity factor) or, more reliably, by tracking your intake at a stable weight for 1–2 weeks. For fat loss, subtract ~10–20% (a 70 kg moderately active person at ~2400 kcal might cut to ~1900–2100). For muscle gain, add ~5–15% (~150–350 kcal). The classic '~3500 kcal ≈ 1 lb of fat' rule is a rough teaching device, not a precise law — adaptive changes in metabolism and NEAT mean real-world results drift from the arithmetic, which is exactly why you adjust by feedback.
What the studies show →
Predictive equations carry real error (individuals can differ from the estimate by 10–20%), and the body adapts — NEAT and metabolic rate shift in response to over- and under-eating, partially offsetting the change. This is well documented and is why no calculated number should be treated as fixed. The reliable method is empirical: set a starting target, track weight trend over 2–3 weeks, and revise the calories if the trend isn't matching the goal. The math gets you in the ballpark; feedback gets you to the target.
Body recomposition — losing fat and gaining muscle at once
It's possible to gain muscle while losing fat ('recomp'), but it's slow, and it works best for specific groups: beginners to resistance training, people returning after a layoff, and those with higher body fat. The recipe is roughly maintenance calories (or a very small deficit), high protein (~1.6–2.2 g/kg), and consistent progressive strength training. For lean, trained individuals, recomp gets very hard — they generally make faster progress by alternating focused gain and loss phases.
For a fat-loss phase, what's a sensible WEEKLY rate of weight loss as a percentage of body weight?
Somewhere between 0 and 5 %.
Reveal the answer →
~0.5–1% of body weight/week
Aiming to lose about 0.5–1% of body weight per week is the sweet spot: fast enough to see steady progress, slow enough to preserve muscle and adherence. For an 80 kg person that's ~0.4–0.8 kg/week. Faster loss increasingly comes from muscle and water, ramps up hunger, and is harder to sustain — patience genuinely pays off in body composition.
Refeeds, diet breaks, and adjusting over time
Long diets benefit from occasional planned higher-calorie days or weeks. They give your hormones, training, and willpower a breather — and as you lose weight, you'll need to lower calories again because a smaller body burns less.
How it works →
A refeed is a short (1–2 day) planned increase in calories, mostly from carbs, during a longer deficit; a diet break is a longer return to maintenance (1–2 weeks). Both aim to ease the adaptive downsides of prolonged dieting — restoring some leptin, replenishing glycogen for training, and relieving the psychological strain. Separately, because your TDEE falls as you lose weight (less mass to maintain, plus adaptive reductions), a deficit that worked at the start eventually becomes maintenance — so you must periodically recalculate and trim again, or increase activity, to keep losing.
What the studies show →
Evidence for structured diet breaks improving fat loss or preserving metabolism is suggestive but mixed — the clearest, most consistent benefit is on adherence and psychological sustainability, which is itself a major determinant of long-term success. Refeeds and breaks aren't mandatory, but they're a sensible tool for longer or more aggressive diets. The non-negotiable principle is feedback-driven adjustment: bodies adapt, so any plan that doesn't get revised over time will eventually stall.
Your weight has stalled three weeks into a fat-loss phase, despite eating the same. What's the most evidence-aligned response?
- Conclude calories don't matter and give up tracking
- Recognise your TDEE has fallen as you lost weight, and modestly cut calories further or add activity
- Cut calories drastically all at once to force the scale down
- Add a large surplus to 'reset' the metabolism
Show the answer →
B.Recognise your TDEE has fallen as you lost weight, and modestly cut calories further or add activity
A smaller body burns fewer calories, and dieting brings adaptive reductions in expenditure, so a once-effective deficit becomes the new maintenance. The fix is a modest further cut or more activity — informed by the trend over weeks — not a drastic crash or giving up. Adjust by feedback; that's the whole game.
Dial in your calorie and macro targets for fat loss, maintenance, or gain, then track the trend over a few weeks and adjust — the feedback loop is what turns a plan into results.