Enough energy to train and recover
In this investigation
Start with the problem I actually had
My first assembled meal was too large and not enjoyable. I stopped eating and discarded much of the rice, beans and remaining chicken. On another day, I liked the food and felt slightly hungry before bed. Neither experience proves a calorie requirement. The useful goal is a daily pattern that I can eat, enjoy and repeat while training and recovering well.
The latest report estimates roughly 3,090 kcal, with a portion/composition scenario of about 2,815–3,500 kcal. That range is not a confidence interval or my measured expenditure. The whole yogurt tub, edible half-chicken weight and oil-heavy chimichurri model materially affect the estimate. It cannot validate an earlier claim that I need more than 3,000 kcal, and it should not overwrite the difference between food bought, eaten and discarded.
Energy availability is a different concept
In sports research, energy availability estimates dietary energy remaining after exercise expenditure, divided by fat-free mass. It asks whether enough energy remains to support the body’s other functions. Energy balance compares intake with total expenditure. A stable body weight does not, by itself, establish healthy energy availability because expenditure and physiology can adapt. IOC consensus, 2023.
Relative Energy Deficiency in Sport (REDs) describes health and performance consequences associated with problematic, rather than every brief, exposure to low availability. It is relevant to men as well as women. Duration, severity, training, carbohydrate availability and individual susceptibility matter. It is not a diagnosis assigned from one food diary, bedtime hunger or shoulder pain.
There is no universal male cutoff
The often-repeated 30 kcal/kg fat-free mass/day is not a universal diagnostic boundary. The 2023 IOC consensus explicitly describes the cutoff as debated in women and less understood in men. It should not become a calculator that tells me I am safe at 31 and harmed at 29. Here, fat-free mass and exercise expenditure are not measured anyway.
Small controlled studies show why a simple threshold is misleading:
- In six exercising men, four days at 15 rather than 40 kcal/kg fat-free mass/day reduced leptin and insulin, but did not significantly change testosterone, T3 or IGF-1. Koehler et al., 2016.
- In 12 male endurance runners, four-day conditions at 45, 30 and 15 were compared. The lowest condition lowered testosterone from 23.8 to 20.3 nmol/L and increased reported fatigue; most other measures were unchanged. The between-condition pattern, not every within-group decline, supported the result. Sim et al., 2024.
- In 11 women and 11 men, five days at 15 versus 45 altered bone-turnover markers significantly within the female group, but not the male group. Crucially, the formal between-sex comparison was not significant either: a significant result in one group and a null result in another is not proof that the sexes differ. Papageorgiou et al., 2017.
- A longer staged experiment in 12 trained male endurance athletes found poorer explosive and endurance performance and worse well-being with reduced availability. Its most severe stage could not be completed for the planned duration by all athletes. Small experimental protocols help identify mechanisms and vulnerability; their proposed ranges are not universal prescriptions. Jurov et al., 2022.
These findings support attention to persistent under-fueling without pretending that one hormone, brief experiment or calorie number diagnoses everyone.
What would make my daily log more useful
My training description includes track intervals and strength training roughly two days out of three, with scooter travel and occasional short city runs or cycling. Calendar time in the gym is not the same as active energy expenditure. A desk job also does not establish either an unusually high or an unusually low maintenance requirement.
For the next practical iteration, record what I ate and when, training duration and effort, appetite, enjoyment, sleep and recovery. Optional morning weights collected under similar conditions can show a trend over several weeks; an individual reading moves with hydration, glycogen and gut contents. Weight is useful context, not a clinical clearance test. Keep planned portions and unknown quantities explicit rather than filling them in retrospectively.
If I am hungry, another simple portion is more useful than forcing a large, unpleasant late bowl. If training output, recovery and weight trends suggest food is insufficient, add food I tolerate and reassess the pattern. Rice or fruit can provide accessible carbohydrate; yogurt, chicken and fish already provide protein. More protein or a recovery supplement cannot substitute for missing total food energy.
Persistent fatigue, declining performance, recurrent bone stress injuries, unintentional weight loss or reduced libido deserve a clinical conversation, especially when food restriction or training escalation accompanies them. These signs also have other causes. The IOC’s methods guidance specifically cautions against deriving a REDs diagnosis from a free-living energy-availability calculation, which has substantial intake and exercise-measurement error. IOC research-methodology guidance.
The immediate improvement is consistent, appetizing food distributed through the day, then adjustment using repeated observations. We do not yet have the evidence to set a precise maintenance target or diagnose low energy availability.