A comprehensive reference covering macronutrients, micronutrients, TDEE, nutrition set up, meal timing, protein quality, hydration, hormonal nutrition, gut health, and evidence-based supplementation.
TDEE Calculator
Calculate your Total Daily Energy Expenditure, then set your calorie target for maintenance, deficit, or surplus. Nutrition set up targets (baseline, low and optional high day) are generated automatically.
Custom Macro Split — must total 100%
Total: — %
Macronutrient Reference
Click any macronutrient for full profile — calories per gram, primary roles, food sources, and practical notes for fitness goals.
Nutrition Set Up
A simple two-tier structure: medium days as your baseline and low days on rest or light activity days. A high carb day is an optional tool, not a default part of the week, and is only added when there is a clear reason (see the notes below). Run the TDEE calculator above to generate your personalised numbers.
Diet Plan Set Up: a single daily target
You don't necessarily need to cycle carbs at all. You can run one single day of intake, the same every day, that covers your weekly trends for the goal at hand: the weekly calorie average for a deficit, maintenance or surplus, with protein, fats and carbs set at levels that support your training. This is often more sustainable and more reliable from a tracking perspective, because there is one set of numbers to hit and any deviations are easy to spot. The medium, low and optional high day structure below is a tool for when there is a specific reason to vary intake, not a requirement.
Nutrition Set Up — General Principles
Day Type
When to Use
Carbs
Protein
Fats
Key Rules
Medium Day
Baseline
Default training day: resistance training, cardio days
Individual. Low end of baseline ≈ 1g/lb
Full protein target
0.3–0.8g/kg
Carbs set to sustain training output, or to fill the remaining calories after minimum protein and fats. Balanced day, most flexible food choices.
Low Day
Rest days, light activity, active recovery
Reduced below baseline as needed
Full or slightly higher
0.3–0.8g/kg
Carb reduction increases the deficit when output is lower. Increase fibrous vegetables to maintain volume. Fats kept in the same range as medium days.
High Day
Optional
Only when needed: fatigue or a diet stall (prep), or weaker bodypart days (growth phase). See notes below.
2–3× medium amount
Same as medium
Same as medium, or reduced if needed
Not a given. Reduce fats only if the high day is a much larger surplus than medium and fat storage risk is a concern. Prioritise rice, oats, potato, fruit.
Your personalised nutrition set up targets — based on TDEE calculator above
High day: prep phase (optional)
In a prep, a high day is only introduced when analysis shows a reason for it: accumulating fatigue (performance dropping, poor recovery, flat or drained training, sleep disruption) or a diet stall (scale weight and measurements flat across a sufficient window despite good adherence). Review adherence, weekly averages, steps and training performance first. If the data points to fatigue or a stall, a high day can restore glycogen, training quality and hormonal signalling. If neither is present, keep it out and stay on the baseline structure.
High day: growth phase (optional)
In a growth phase, a high day can be used to support a weaker bodypart. Place it either on the day of that bodypart's session or the day before, so glycogen is topped up going into the session. It is not needed for every training week and is not required to grow. Use it where it has a clear purpose, for example to push training quality on a lagging muscle group.
Carbs: medium days
Carbs are individual. Set them to sustain training output, or to fill the calorie gap left after minimum protein and fats have been allocated to hit the calorie target. The low end of baseline, before any further deficit is applied, is about 1g per lb of body weight.
Carbs: low days
Carb reductions on low days can be used to increase the overall deficit when output is lower on those days (rest days, lighter sessions). Reduce below baseline only as far as the goal requires, and keep an eye on training performance the following day.
Fats: medium and low days
Fats sit at 0.3–0.8g/kg depending on individual needs. Natural athletes will likely sit at the higher end of that range to support hormonal health.
Fats: high day
Fats can stay the same as the medium day. They can be reduced if needed when the high day is a much larger surplus than medium day calories, to lower fat storage risk: when carbohydrate intake is high, insulin is elevated and dietary fat is preferentially stored in that environment.
Carb sources matter
If a high day is used, prioritise fast-digesting carbs around training (white rice, fruit, potato) and slower sources earlier in the day (oats, sweet potato). On low days keep carbs from fibrous vegetables — they contribute minimal net carbohydrate and maintain micronutrient intake.
Weekly average is what matters
Most weeks run on medium and low days alone. When a high day is added, the weekly caloric average should still align with your goal — deficit for fat loss, surplus for muscle gain — so the extra calories are offset elsewhere in the week if needed. Individual day variation is a tool, not the goal itself, and a single daily target that matches the weekly average is a perfectly valid set up.
Protein stays constant
Protein intake should remain at your target across all day types. Protein's thermic effect (25–30% of calories burned in digestion), satiety, and muscle protein synthesis benefits are consistent regardless of carb or fat intake on that day.
Protein sparing on high days
On a high carbohydrate day, carbs act as a protein-sparing nutrient — elevated insulin and glucose availability reduces the body's reliance on amino acids for energy. Some individuals can modestly reduce protein intake on high days (e.g. 1.6–1.8g/kg instead of 2.0g/kg) without compromising MPS, as long as total weekly protein averages remain at target. This is an advanced optional adjustment — not mandatory — that can free up additional calories for carbohydrates.
Micronutrient Reference
RDI values shown for athletic males and females. Athletic populations typically require 20–50% above standard RDI for several key micronutrients due to sweat losses, increased oxidative stress, and higher metabolic demand.
Meal Timing & Nutrient Partitioning
When you eat matters — not as much as what you eat overall, but enough to meaningfully affect training performance, recovery, and body composition when total intake is dialled in.
Protein Quality
Not all protein is equal. DIAAS (Digestible Indispensable Amino Acid Score) is the current gold standard for protein quality assessment. Leucine content per serving is the primary trigger for muscle protein synthesis.
Glycaemic Index & Insulin Response
Glycaemic Index (GI) measures how quickly a food raises blood glucose relative to pure glucose (GI 100). Glycaemic Load (GL) accounts for serving size — a more practical measure. Context determines whether high or low GI foods are appropriate.
Fibre Guide
Dietary fibre is one of the most undervalued nutrition variables in fitness. Beyond digestion, fibre directly influences body composition, hormonal health, micronutrient absorption, and training recovery via the gut-inflammation axis.
Hydration & Electrolytes
Performance begins to decline at just 1–2% body weight loss through sweat. Hydration affects strength output, endurance, cognitive function, and nutrient transport.
Hormonal Nutrition
Dietary choices directly regulate the hormonal environment — testosterone, cortisol, insulin, thyroid, and growth hormone are all meaningfully influenced by macronutrient distribution, caloric availability, and specific micronutrients.
Gut Health & Absorption
The gut is where nutrition actually happens. Optimal macronutrient intake means nothing if absorption is compromised. Gut integrity, microbiome diversity, and digestive enzyme activity all influence how effectively you absorb what you eat.
Evidence-Based Supplements
Only supplements with meaningful, replicated evidence in healthy athletic populations. Evidence rating: 5 dots = Tier 1 (consistent strong evidence), 1 dot = limited or mixed evidence.