Reverse dieting and maintenance roadmap

What the tool does

It estimates your maintenance, compares it with what you actually eat and, when you are clearly below it, lays out weekly calorie and macro targets that stop at the initial estimate. From then on, only your check-ins decide whether to increase, hold or reassess. It never plans below your estimated resting energy expenditure and does not predict weight, fat or muscle changes.

Validated equations and established methods

• Resting energy expenditure: Mifflin–St Jeor (Mifflin et al. 1990), or the Katch–McArdle lean-mass equation (370 + 21.6 × lean mass in kg) when you enter body fat. Both are population equations with individual error.
• Cardio: net energy cost from metabolic equivalents (MET − 1) × bodyweight × hours, with 1 MET ≈ 1 kcal per kg per hour (2024 Adult Compendium of Physical Activities). Easy = 3.5, moderate = 5 and hard = 8 METs are our approximations of those intensity ranges.
• Energy in body-weight change: 7,700 kcal per kg is an approximation. The energy content of weight change depends on body composition and changes over time (Hall 2008; Hall et al. 2011), so we use it only to read short trends.

Coaching conventions (adjustable, not validated doses)

• Maintenance = resting energy × 1.2 for basic daily living and digestion, plus steps × 0.0004 kcal per kg of bodyweight (about 0.5 kcal per kg per km of walking at roughly 1,300 steps per km), plus about 300 kcal per strength session averaged over the week, plus cardio. These are the same rules as the site’s other calculators; steps are counted once and the 1.2 factor does not include walking.
• Maintenance is treated as a band of about ± 250 kcal. “Near maintenance” means within 150 kcal of the planning estimate.
• Weekly increments of 50, 100 or 150 kcal, weekly reviews, and a provisional ramp that stops at the initial estimate: weekTarget = min(starting intake + increment × week, initial maintenance estimate).
• Refinement from your data: observed maintenance ≈ average intake − (weekly weight change in kg × 7,700 ÷ 7), weighted 50% against the equation with three weekly weights, 75% with four or five, 25% less when fewer than five days are tracked.
• Check-in thresholds: weight “stable” within ± 0.2% of bodyweight a week; at least 5 tracked days; activity counted as changed when steps move by more than 25% (and more than 1,500 steps) or strength sessions by 2 or more; intake counted as off target when it differs by more than 100 kcal or 7.5%.
• Protein and fat: the site’s rules (protein rises in a deficit and is never reduced as calories rise; fat at least 0.6 g per kg of bodyweight and 20% of calories; carbohydrate takes the rest; grams rounded to 5, calories to 10).
• Safety rules: resting energy expenditure is a conservative product limit, not a medical threshold. An intake below 75% of it after a deficit of 12 weeks or more is treated as prolonged severe restriction.

The principles behind the plan, and the studies that support them

Start from actual current intake, increase calories in manageable steps, keep protein adequate and resistance training in place, review average weight, activity, adherence and recovery, and adjust to what you observe. Each principle is supported by the studies below: energy expenditure adapts during a diet (Trexler et al. 2014); enough protein together with resistance training protects lean mass (Helms et al. 2014; Morton et al. 2018); weight change reflects energy balance over weeks, not days (Hall 2008; Hall et al. 2011); and prolonged low energy availability harms health and performance (Mountjoy et al. 2018, 2023). Research on reverse dieting itself is still limited (Trexler et al. 2014), so no single method has been proven best.

Sources

• Trexler ET, Smith-Ryan AE, Norton LE. Metabolic adaptation to weight loss: implications for the athlete. J Int Soc Sports Nutr 2014;11:7.
• Mifflin MD et al. A new predictive equation for resting energy expenditure in healthy individuals. Am J Clin Nutr 1990.
• Hall KD. What is the required energy deficit per unit weight loss? Int J Obes 2008;32:573–576.
• Hall KD et al. Quantification of the effect of energy imbalance on bodyweight. Lancet 2011;378(9793).
• Helms ER, Aragon AA, Fitschen PJ. Evidence-based recommendations for natural bodybuilding contest preparation: nutrition and supplementation. J Int Soc Sports Nutr 2014.
• Helms ER et al. A systematic review of dietary protein during caloric restriction in resistance trained lean athletes: a case for higher intakes. Int J Sport Nutr Exerc Metab 2014.
• Morton RW et al. A systematic review, meta-analysis and meta-regression of the effect of protein supplementation on resistance training-induced gains in muscle mass and strength in healthy adults. Br J Sports Med 2018.
• Mountjoy M et al. IOC consensus statement on relative energy deficiency in sport (RED-S): 2018 update. Br J Sports Med 2018;52:687–697.
• Mountjoy M et al. 2023 International Olympic Committee’s (IOC) consensus statement on Relative Energy Deficiency in Sport (REDs). Br J Sports Med 2023;57:1073–1097.
• Herrmann SD et al. 2024 Adult Compendium of Physical Activities. J Sport Health Sci 2024;13:6–12.

The underfuelling and suitability messages follow the IOC consensus statements: low energy availability can affect hormones, bone, immunity, recovery and performance, and needs individual assessment.