We estimate resting energy with Mifflin–St Jeor: 10 × weight (kg) + 6.25 × height (cm) − 5 × age, plus 5 for the male equation or minus 161 for the female equation. The selected activity factor (1.30–1.75) estimates a typical whole week. These factors are practical assumptions, not measured metabolism. The ±15% band illustrates uncertainty; it is not a statistical confidence interval.

Fat-loss choices use about 10%, 15% or 25% below estimated maintenance, capped at 300, 500 or 750 kcal/day respectively, rounded to 25 kcal. The deficit is reduced to keep the suggested intake at or above 1,500 kcal/day. These choices are tool design assumptions, not clinically validated personal prescriptions. Muscle gain uses a modest 5% surplus, rounded to 25 kcal and capped at 250 kcal/day; muscle gain without any fat gain cannot be guaranteed. No deficit is offered below BMI 20. These are conservative limits for this self-service tool, not universal nutrition rules. BMI is only a screening check; it does not measure body fat. The tool does not generate plans for BMI below 18.5 or 40 and above, or the situations listed in step 1.

Macro starting targets: protein 2 g/kg of current body weight (rounded to the nearest gram); fat about 30% for Balanced or 35% for Moderately lower carb; carbohydrate takes the remainder using 4/4/9 kcal per gram. This is one practical split, not a uniquely optimal diet. Menu totals come from the actual listed portions. CoFID carbohydrate is reported as monosaccharide equivalents and its energy uses 3.75 kcal/g for carbohydrate; food totals therefore need not equal the 4/4/9 target arithmetic. Naked Tofoo and optional powders use named product labels. Whey fibre is undeclared and treated as zero; trace values are treated as zero. Food portions are rounded to 5 g and actual totals are always shown. A menu is flagged when it differs by more than 5% in energy or 10% in protein. Experience changes training and recovery guidance; it does not independently change the calorie equation or the 2 g/kg protein target. Training plans are practical starting templates, not a test of individual capacity.

Automatic menus support estimated targets of 1,500–4,000 kcal/day. Outside that range, the tool shows energy estimates and training without a menu. The planner offers general example menus; it does not assess every vitamin/mineral or guarantee weight change. Review your energy, hunger, performance and longer-term weight trend after 2–4 weeks. Seek a registered dietitian for individual needs or persistent problems. No health answers are saved by this planner or attached to orders; reloading clears the form. A downloaded plan is saved on your device.

• NICE NG246 — supported dietary approaches
• Helms et al. 2023 — small and large energy surpluses
• NIDDK — eating and activity for weight management
• Mifflin et al. — original resting-energy equation
• ISSN — protein and exercise position stand
• NHS — adult physical activity guidance
• ACSM — 2026 resistance training guidance
• NHS — Eatwell Guide
• CoFID 2021 — UK food composition dataset · contains public sector information licensed under the Open Government Licence v3.0
• Naked Tofoo — food label reference

Powder references: Myprotein Impact Whey, Vanilla · The Source Organic Pea Protein. The planner does not sell or require these brands; check your own label.

Meal-prep ideas reviewed: Myprotein, Gymshark, Bulk and PureGym. Our original menus use simple repeatable ingredients; these brands are not the source of the calorie equation.

Food Standards Agency: food storage and reheating · NHS: meat in your diet

Research checked 7 October 2026. GymFitLab is not affiliated with or endorsed by these organisations.

Training split: A covers upper body and B covers legs/core. Two days are an introductory schedule; three days alternate A/B/A and B/A/B. Four days train each region twice weekly. Build frequency gradually as recovery allows. ACSM resistance-training guidance.