Nutrition fundamentals guide.

Nutrition Fundamentals Guide — Free Interactive Reference · Bodybuilding with Aaron

Most people know they should eat better. Very few understand why specific foods, macros, and timing actually change the way their body looks and performs.

The Nutrition Fundamentals Guide is a comprehensive interactive reference built for anyone who trains — whether you're just getting started or you've been in the gym for years and want to finally understand the science behind what you're eating.

This isn't a meal plan. It's a framework. One you can apply to any diet, any goal, and any lifestyle — because it teaches you how nutrition actually works, not just what to eat.

What's inside:

• TDEE Calculator — calculate your Total Daily Energy Expenditure, set your calorie target for maintenance, deficit, or surplus, and generate a personalised carb cycling day breakdown automatically. Includes a custom macro percentage split tool so you can set your own protein, carb, and fat ratios
• Macronutrients in full — protein, carbohydrates, and fats covered in complete detail, including calories per gram, primary roles, food sources, and fitness-specific applications. Full breakdown of MUFA, PUFA, saturated, and trans fats
• Carb cycling framework — high, medium, and low day structure with the reasoning behind each, including why fats should be trace-only on high days and how carbs act as a protein-sparing nutrient
• 13+ micronutrients — physiological function, cofactors, deficiency signs, and athletic RDI for both males and females across vitamins and minerals
• Meal timing & nutrient partitioning — pre-workout, intra, post-workout, pre-sleep, and morning windows with practical guidance for each
• Protein quality guide — DIAAS scores, leucine content, absorption speeds, and best-use context for 11 protein sources, including beef, pork, white fish, shellfish, whey, casein, and plant sources
• Glycaemic index & insulin response — GI and GL scores for 20+ foods, organised by low, medium, and high categories with context on when each is appropriate
• Fibre guide — soluble, insoluble, and resistant starch with fitness-specific roles and gut health implications
• Hydration & electrolytes — daily targets for athletic populations with flexible ranges for sodium and potassium based on training volume and sweat rate
• Hormonal nutrition — how dietary fat, carbohydrates, and specific micronutrients directly regulate testosterone, cortisol, insulin, thyroid, and growth hormone
• Gut health & absorption — gut integrity, microbiome, digestive enzymes, and probiotics explained in practical terms
• 20+ evidence-rated supplements — creatine, caffeine, omega-3, vitamin D3/K2, magnesium, TUDCA, NAC, CoQ10/ubiquinol, PQQ, carnitine, taurine, nattokinase, glutathione, and more — each with mechanism, benefits, dosing, and a 5-point evidence rating

Format

Fully interactive HTML file — open directly in any browser, no app or download required. Filterable sections, expandable cards, and a live calculator. Works on desktop and tablet.

Free. No fluff. Just the framework.

For educational use only. Individual needs vary — always consult a qualified nutritionist for personalised advice. Produced by Bodybuilding with Aaron using Claude AI.