This is not really a surprise. Brits who travel abroad tend to be older and so the healthcare they get abroad is more expensive. Other EU citizens who come to the UK are relatively younger and healthier, so they are less likely to need medical treatment while they’re here.
In reality, only 3.6% of the UK population is from another EU country. Most migration in the UK is from outside the EU, which means freedom of movement rules don’t apply and it’s completely up to the British government how to manage this migration. Evidence
And EU migrants are net contributors to the economy. Between 2001 and 2011, they contributed 34% more in taxes than they took out in benefits and services. Evidence
Compared to the UK average, EU migrants are more highly educated, more likely to be employed, and much less likely to claim benefits. Evidence