Feast and famine: does brunching help your mood?

Fasting is having a moment in the spotlight and it has certainly helped me feel better in my daily life. But how much of the advice is rooted in strong evidence?

Photo by Christopher Jolly

In the world of dietary interventions, fasting is a new powerful contender. The literature is growing rapidly with a cascade of potential benefits, from better gut health to happier mood. Recent studies, particularly the Big Intermittent Fasting (Big IF) study run by the ZOE Health Study team, have emphasised the potential impact of fasting and time-restricted eating (TRE) on our health.

Fasting is a big umbrella term and is used to refer to strict diets of  episodic calorie restriction. Religious fasting is wide-spread with millions of people undertaking religious fasts every year with variable impacts on health, whilst modern popular fasting diets like the  5:2 diets or just drinking water for 48 hours are more niche. Followers of these diets claim huge benefits, but studies showed most people couldn't adhere to them long term and taking the expensive Swiss clinic retreat isn’t within everyone’s budget, so ultimately they have failed to become truly popular. The exception may be the newest form - time restricted eating (TRE), which changes the timing of meals but not the total calories consumed.

One notable revelation from the Big IF study, a large community science experiment involving more than 100,000 people, that I didn't expect, is the major role of fasting in mood and energy levels. The findings show that when individuals consume food in a simple 10 hour eating window, not only does hunger subside, but mood improves as well. And here's a clincher – the simple act of delaying breakfast to later in the day can also produce these benefits. It’s worth noting that circadian rhythm science points to the importance of regular, predictable meal times, so having a meal around the same time every day is really helpful for our internal clock to align and know what to expect.

The concept of brunch, as opposed to the traditional early morning breakfast, is gaining traction as a great meal to initiate the day. The long-held belief (and still in NHS official guidelines) that breakfast is indispensable to kick-start our mornings is looking outdated, as are the worries that without it we are destined to overeat, suffer loss of concentration and energy. A meta-analysis of trials points to breakfast as a healthy intervention as quite simply not true.