Strong evidence

Persistently eating too little for the training you do harms bone, hormonal and metabolic health, not just performance.

In practice

If training is going backwards while you're eating less and less, that's a signal to eat more, not to train harder. This affects men as well as women, and recreational trainees as well as athletes.

What it doesn't say

Recognising this pattern is a clinical matter. If it sounds familiar, that's a conversation with a doctor or a registered dietitian, not with an app.

Source

• Mountjoy M, Ackerman KE, Bailey DM, Burke LM, Constantini N, Hackney AC, Heikura IA, Melin A, Pensgaard AM, Stellingwerff T, Sundgot-Borgen JK, Torstveit MK, Jacobsen AU, Verhagen E, Budgett R, Engebretsen L, Erdener U (2023). 2023 International Olympic Committee's (IOC) consensus statement on Relative Energy Deficiency in Sport (REDs). British Journal of Sports Medicine, 57(17):1073–1097. doi.org/10.1136/bjsports-2023-106994