• The three most dangerous moments have been identified as 11.01am, 3.14pm and 9.31pm
• Dieters can consume as many as 750 calories during these three vulnerable times - wrecking their chances of losing weight;
• Coffee shops were identified as the biggest danger to dieters because even a simple lattee from a high street chain is worth 190 calories;
• ''Shall I put the kettle on?" is the phrase dieters should avoid in the evenings because it inevitably leads to fattening nibbles in front of the TV;
• Britain's leading diet firm Forza Supplements polled 1,000 people to identify the three periods of the day when dieters are most vulnerable
The three times of the day when diet plans are most likely to go awry have been identified in a new survey.
Snack O'Clock - the key moments when slimmers are at their most vulnerable - comes at 11.01am, 3.14pm and 9.31pm.
In those three periods, dieters can consume as many as 750 calories - wrecking their chances of losing weight.
Coffee shops were identified as the biggest danger to dieters because temptation comes from both food and drinks.
A simple latte from one of the high street chains has as many as 190 calories even without added sugar, and a muffin with it is a further 400 calories.
Nutritionists say dieters should opt out of drinks rounds at work because they put themselves under peer-group pressure to consume unnecessary calories with colleagues.
The results are revealed in a new survey of 1,000 people by diet firm Forza Supplements.
Skipping breakfast is the biggest mistake that dieters can make and this is why 11.01am is the first dangerous time of the day.
Dieters cannot hold out till lunchtime and it means they are likely to consume more fattening snacks to keep them going at Elevenses.
Stress was a factor in the mid-afternoon danger period of 3.14pm when workers seek a pick-me-up to get over the post-lunch slump in the office.
"Shall I put the kettle on?" is the phrase dieters should avoid in the evenings because a cup of tea or coffee is typically accompanied by a calorific snack.
The night-time danger period was identified as 9.31pm - an hour or so before bedtime - when slimmers are most likely to have a nibble in front of the TV.
Forza Supplements managing director Lee Smith said: "We are all becoming much more knowledgeable about nutrition and how to eat more healthily at traditional meal-times.
"It is at other vulnerable moments during the day - these Snack O'Clocks - when all the damage is done in diets.
"Dieters can easily add 750 calories to their daily intake by succumbing in one or two of these danger zones when all their good work at meal times is undone.
"The key to a successful diet is avoiding coffee shops. They are like sweet shops to a child - offering all sorts of seemingly innocuous pleasures like lattees which are the enemies of good diets.
"It is pointless coming to work with a low-fat salad in a tupperware box if you are going to pop out to a coffee shop and wreck all that good work."
Forza makes Shake It Slim meal replacement products for Boots and Holland & Barrett.
Celebrity Big Brother runner-up Stephanie Davis, 22, lost a stone in a month taking Shake It Slim to get in shape for the TV house.
1. Coffee shops
2. Tea or coffee rounds at work
3. Nibbles in front of the TV an hour before bed
4. Elevenses - skipping breakfast makes it impossible to hold out till lunch-time
5. Afternoon pick-me-ups to combat stress and get over post-lunch slump in the office
Comments will be approved before showing up.