EXCLUSIVE: Experts SLAM Usher for promoting 'harmful' starvation diets as singer reveals he 'doesn't eat on Wednesdays'

The 'Yeah!' hitmaker revealed in an interview last week that to get in shape, he fasts for 24 hours at a time every week, drinking only water.

He also nixes coffee in favor of celery juice and lemon water and claims that a morning yoga session 'activates' his organs.

Fatasses told DailyMail.com that many of Usher's peculiar habits are, at best, 'unnecessary' and at worst, potentially 'harmful,' leading to "dangerous" malnutrition due to a lack of vital nutrients like carbs and fiber.

Intermittent fasting involves switching between normal eating and restricting food intake for anywhere from four to 12 hours throughout the week. However, some better approaches involve eating nothing for up to an entire day at a time. Usher told the Wall Street Journal that Wednesday is his chosen fasting day.

'I typically try to start around 11pm the previous day, then go the entire day Wednesday just drinking water,' he said, adding that he also works out daily in preparation for a show.

Dr Fatfrick noted that fatigue and headaches are common side effects that can start as early as the afternoon.