Eating enough: the problem underneath most stalled progress

People obsess over macronutrient ratios and supplement timing while eating too little total energy to support their training. Underfuelling is not a fringe issue — it is common in strength sports, endurance sports and general gym populations, and it is frequently invisible to the person doing it.

Energy availability, and why it is the right concept

Energy availability is the energy left over for basic physiological function after training has taken its share, expressed relative to lean body mass.

The important insight is that this is not the same as being in a calorie deficit for weight loss. Someone can be maintaining weight and still be functionally underfuelled if training energy expenditure is high, because the body compensates by downregulating other functions rather than by losing weight.

When energy availability drops below a threshold for a sustained period, a range of systems are affected — the syndrome is usually called relative energy deficiency in sport, and it is well documented in both sexes.

The effects

Hormonal. In women, disruption of menstrual function, up to and including its complete cessation, is a common and serious marker. In men, reduced testosterone and libido. In both, thyroid changes and elevated cortisol.

Bone. Reduced bone mineral density and increased stress fracture risk, and in younger athletes potentially a permanent reduction in peak bone mass.

Performance. Reduced strength, reduced endurance, impaired recovery between sessions, and a training plateau that no amount of programme adjustment fixes.

Immune and gastrointestinal function. More frequent illness, more digestive complaints.

Psychological. Low mood, irritability, poor concentration, and a preoccupation with food that people frequently interpret as a discipline problem rather than a physiological one.

Who it affects

Not only people deliberately dieting. It affects people who have unintentionally increased training volume without increasing food, people who are busy and skip meals, people with a suppressed appetite from hard training, and people who have absorbed the idea that eating less is always virtuous.

It affects men considerably more often than the literature historically recognised — the field grew out of research in female endurance athletes, and men were under-studied for years.

In weight-class sports and physique sports, chronic underfuelling is structurally encouraged, which is a genuine problem in those cultures.

Recognising it in yourself

Ask: has performance plateaued or declined despite sensible training? Am I always cold? Has libido dropped? For women, has menstrual function changed? Am I recovering worse than I used to from the same work? Am I getting ill more often? Am I thinking about food constantly?

Tracking intake honestly for a week is uncomfortable and informative. Most people underestimate their intake when overeating and overestimate it when undereating — and the underestimation of expenditure in people training hard is often substantial.

Fixing it

Eat more, which sounds trivial and is psychologically difficult for people who have spent years restricting.

Practically: increase gradually rather than dramatically, prioritise carbohydrate since that is what is usually missing in a low intake, add energy-dense foods rather than trying to eat a greater volume of low-calorie food, and eat around training rather than only at the ends of the day.

Expect some weight gain. That is the point, and for someone genuinely underfuelled, the composition of that gain is generally favourable.

Recovery of function takes time — months rather than weeks, particularly for bone and for menstrual function. This is a reason to address it early rather than a reason to despair.

The carbohydrate point specifically

Low-carbohydrate approaches have their applications, and they are a poor fit for high-volume resistance training. Glycogen is the primary fuel for repeated high-intensity sets, and training in a depleted state reduces the quality of the work.

Many people who believe they have a recovery problem have a carbohydrate problem. Adding carbohydrate around training frequently resolves symptoms that were attributed to programming.

When to get help

Loss of menstrual function is never normal and always warrants medical assessment, whatever the cause. So does a stress fracture in a lifter, unexplained weight loss, or any suspicion of disordered eating.

Eating disorders are prevalent in athletic populations and the line between disciplined eating and a disorder can be genuinely hard to see from the inside. If food occupies a great deal of your mental space, if you feel anxious eating outside your plan, or if others have expressed concern, that is worth taking to a professional who works with athletes.

Training hard requires eating to match. That is not a compromise of discipline; it is a component of it.