Why has an ad for Huel meal replacement shakes been banned?

Why has an ad for Huel meal replacement shakes been banned? The advertising watchdog, the ASA, ruled that the ad, which featured brand ambassador Spencer Matthews, encouraged or condoned an irresponsible dietary practice. It said the ad suggested that replacing all normal food with Huel was nutritionally appropriate and no barrier to a high level of physical performance. Huel says it respects the decision and has complied, and that the ad was meant to challenge the idea that Huel should replace every meal. The ad can’t appear again in that form.