Whole specimen on pure sugar
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Every kcal of today's expenditure delivered as glucose. Real bodies burn a fat/carb mix.
Specimen
Sex
BMR—
TDEE (from routine)—
A day in the life —
Energy is summed from MET × mass × hours, so a full day should total 24 h.
| Activity | Name | Hours | MET |
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Liver gluconeogenesis suppressed not a goal
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Matches basal hepatic glucose output (≈2 mg·kg⁻¹·min⁻¹). The number you'd avoid, not chase.
Bare obligate minimum
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What the brain, red blood cells & renal medulla strictly require.
The three figures, compared
Glucose in g/day; obligate bar shows the 1.7–2.3 g/kg band.
Demand vs body mass
Each tier vs mass for the current routine. ● marks your specimen.
Where the day's energy goes
kcal per activity (MET × mass × hours).
Whole-body glucose vs how hard the day is
Across average daily MET. ● marks today.
Reference ranges for a healthy adult — not a personal prescription. Protein at 4 kcal/g; %-energy is relative to your TDEE.
RDA floor
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The 0.8 g/kg intake that keeps 97.5% of adults in nitrogen balance. A floor, not an optimum.
Active / general fitness
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Typical range for regularly active people maintaining muscle.
Resistance / athlete
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Range associated with building or sparing muscle under heavy training.
Protein tiers
Daily protein in g/day across the three reference tiers.
Reference ranges for a healthy adult — not a personal prescription. Fat at 9 kcal/g; the AMDR is an energy-share band of your TDEE.
Essential minimum
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Roughly the structural / essential-fatty-acid floor (linoleic + α-linolenic, membranes, fat-soluble vitamins).
AMDR energy-share range
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The 20–35% of total energy commonly recommended as the working range for dietary fat.
Fat: essential floor vs AMDR range
Daily fat in g/day.
Build a day's macros against your TDEE (). Energy balance is approximate; the weekly-mass estimate uses ~7,700 kcal per kg and ignores water, glycogen and adaptation.
Calculate Optimum
Declare a goal and assumptions; the engine enforces reality — it blocks the impossible and warns the inadvisable — then fills the builder with a target and explains why.
Mode
Total energy—
Split C/P/F—
Vs TDEE—
Est. weekly change—
Energy by macro vs TDEE
Stacked kcal; dashed line marks your TDEE.
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Carbs—
Protein—
Fat—
Energy by macro vs TDEE
Grams computed to hit your TDEE exactly at the chosen split.
The actual science
Energy densities (Atwater). Carbohydrate and protein ≈ 4 kcal/g, fat ≈ 9 kcal/g. Pure glucose specifically is 3.72 kcal/g (2805 kJ/mol ÷ 180.16 g/mol), which the Carbs/Glucose tab uses for its tiers.
"Natural sugar" is not a thing. The calculator counts carbohydrate by the gram and gives no credit for sugar being "natural", because there is no such molecule. Glucose from a date is identical to glucose from a cola; fructose from agave, honey or fruit is the same fructose your liver sees from syrup. What differs is the package, not the sugar: whole fruit wraps it in fibre, water and bulk that slow absorption and cap the dose — juice it, dry it into dates or boil it to syrup and that advantage is gone. "Natural" sweeteners (agave, coconut sugar, maple) are the same sugars; agave is in fact higher in fructose than corn syrup.
BMR & TDEE. Mifflin-St Jeor for BMR; TDEE from the routine as Σ(MET × mass × hours), 1 MET ≈ 1 kcal·kg⁻¹·h⁻¹.
Glucose tiers. Whole-on-sugar = TDEE ÷ 3.72; GNG-off = 2.88 g·kg⁻¹·day⁻¹ (2 mg·kg⁻¹·min⁻¹); obligate 1.7–2.3 g·kg⁻¹·day⁻¹.
Protein. RDA 0.8 g/kg (nitrogen balance for 97.5% of adults); active 1.2–1.6 g/kg; resistance/athlete 1.6–2.2 g/kg.
Fat. Essential/structural floor ≈ 0.5 g/kg; AMDR working range 20–35% of total energy.
Custom builder. Grams mode sums macro energy and compares with TDEE; split mode divides TDEE by the chosen energy shares. The weekly-mass figure uses ~7,700 kcal/kg and is a rough guide only.
Caveat: these are population reference ranges and back-of-envelope energetics, not individual prescriptions. Real requirements vary with genetics, health, training and goals.