Fat o'clock – the time in the week when we are most likely to start comfort eating and pile on the pounds – starts at precisely 7pm on Sunday nights. 

Almost half of those questioned (48 per cent) nominated the three hours between 7pm and 10pm on Sundays as the time that they were most vulnerable to the cravings of comfort food like crisps and biscuits.

The other danger zone for dieters was between 3pm and 5pm in the afternoon, chosen by 28 per cent of respondents.

Late afternoon - between 5pm and 7pm – was the third most popular time for abandoning healthy eating plans with 13 per cent saying that is when they are most likely to succumb to calorific treats.

The findings come from a new survey that also shows that weekends are, unsurprisingly, when we comfort eat the most with Sundays (chosen by 16 per cent of those surveyed) the most popular non-diet days.

Mondays, perhaps surprisingly, are also popular for snacks – with 12 per cent saying they are most likely to comfort eat then, possibly to get over the misery of being back at work.

Respondents were also asked at which meal they were most likely to over-eat.

The first choice was overwhelmingly dinner – chosen by 65 per cent of those polled, followed by supper (22 per cent), lunch (16 per cent) and breakfast (just 3 per cent).

A third (34 per cent) of comfort eaters scoff two units after succumbing to hunger pangs – one unit being a packet of crisps, a biscuit, a piece of toast or a chocolate snack.

More than one in five (22 per cent) said they had three units, with one unit the next popular answer (17 per cent).

A sizeable number (11 per cent) have between four and five units, and 8 per cent munch their way through more than five units of naught foods. 

Diet experts say a key factor in the increase in comfort eating is mood swings.

A staggering 65 per cent of those surveyed said they were more likely to hit the cookie jar if they have had a bad day at work. 

Skipping breakfast also makes us turn to the sinful foods, with 41 per cent of us skipping breakfast at least half of the week. 

In line with the existing advice to dieters to always eat first thing, more than a third of those who don’t eat breakfast (36 per cent) admit that they eat more at night-time. 

Another factor encouraging comfort eating is eating lunch at your desk. 

Almost half of us (46 per cent) have lunch at our desks  - and half of those say this encourages them to eat more later.

The survey on eating habits was conducted by Forza, who sell Raspberry Ketone – the diet supplement on which ex-Emmerdale beauty Roxanne Pallett used to lose more than a stone.

Forza chief executive Lee Smith said: 'Fat O’Clock is a nightmare for all dieters. It’s that time when you are especially vulnerable and the only thing that is going to stop your cravings is padlock on the pantry.

'It is useful for everyone to know the exact times of those danger spots so that they can eat more sensibly on those days.’