The waistlines of women suffer the most, with the average female putting on 6lb 3oz - the equivalent of a whole dress size - while men see their weight increase by 5lb 2oz, the Daily Mail reported.
The report into our eating habits found that, on average, we eat at least two snacks a day, with 30 percent of us tucking into three or more.
Women admit eating more than men, with a further 13 percent of ladies scoffing four or more snacks a day.
The research, by The Village Bakery, found that eating the wrong things at lunch may mean we are continually drawn to unhealthy, calorific treats.
Biscuits are the most common vice, with 42 percent regularly opening a pack, closely followed by chocolate (38 percent), crisps (32 percent) and cakes (13 percent).
And office workers are worse than most. Cakes and biscuits brought into work by colleagues are one of the main temptations office staff give in to.
In addition, 33 percent admit reaching for nibbles to cope with stress and 22 percent said that they need a sugar rush to perk them up in the afternoon.
Unfortunately, it's not as if we are likely to do anything positive to counteract the sweet treats.
A fifth of women confess spending the evening regretting the day's calorie intake, twice as many as men.
And a mere six per cent of us do something healthy, such as go to the gym.
For one in ten, snacking during the day sparks an unhealthy domino effect - as they've already blown their diet, there's no point in eating healthily that evening either.
The report indicates that not eating a filling lunch could be the reason so many of us are drawn to sugary and fatty snacks.
48 percent admit not feeling full or satisfied after lunch.
Office workers are most likely to get hungry again and snack more, with 35 percent reaching for treats, compared to 14 percent of non-office workers.