Fitness First's report reveals that 75% of fathers in Britain are admitting to putting on weight during the pregnancy stage and the first year of fatherhood.
The results show that fathers are gaining almost a stone during their partner's pregnancy, the average being 11 pounds, more than the 7.3 pound weight of an average newborn.
Dubbed the 'preg-man-cy' weight, the report revealed that new fathers such as Benedict Cumberbatch and 'second-time dad' Prince William are not in the clear as the male baby weight gain continues into the first year of fatherhood.
Almost two thirds of dads said they put on an extra 7.5 pounds throughout the life-changing first year, nudging the average total baby weight gain for men to 18.5 pounds.
Kate Toland, Head of Marketing at Fitness First said "As a nation, we're very focused on guidelines of health and fitness for mums-to-be, but this research shows that men are also in need of a bit of guidance during this life-changing' time."
She continues "And it starts way in advance of baby arriving with only 20% of men saying they maintained a diet with healthy portions throughout their partner's pregnancy."
In addition, a surprising 13% of men admitted that while their pregnant partner's eating habits didn't change, theirs did, as they ate to make up for going out less.
Over 30% said they were affected by their other half's unhealthy cravings and 24% of dads-to-be actually increased their portion sizes to compensate for the fact that their pregnant partner stopped leaving leftovers.
Also, exercise dropped significantly for dads during the first year of their baby's life; with the average number of exercise sessions dropping from three to four before the birth of their child, to one to two sessions once baby arrived.
The Fitness First study also revealed that dads in Birmingham and London exercise the most before the birth of their child, with an average of four to five sessions a week, but even these drop down to three sessions per week with the new arrival.
Cardiff, Sheffield and Wolverhampton are the only cities where dads managed to maintain their pre-birth schedules during the first year of their newborn's life, averaging at around two sessions per week.
Kate Toland continues "It's great that dads are supporting their partners through pregnancy and beyond but we want to ensure British dads are in the best shape they can be for their families, and that means avoiding too much 'sympathy weight'."
"Using exercise to support you through big life changes is key to maintaining long-term health. Increasing exercise during the pregnancy phase is one way for dads-to-be to counteract a decreased focus on healthy eating; it also ensures that when they inevitably lessen the number of fitness sessions after the birth, they are in better shape already."
"Stress also plays a role in weight gain with dads upping their alcohol intake after their child is born in a bid to reduce tension. Two-thirds of dads drink the equivalent of two pints a week extra following the birth of their child, and one in five crave sugary foods to help cope with sleepless nights."
"Exercise also helps with stress relief, and while it can't help with every new parent's problem of no sleep, it can help improve the quality of sleep you get. Even short bursts of 20 minutes of exercise a couple of times a week could help improve sleep, stress levels and maintain a good level of fitness."
Fitness First have three top tips for preventing the 'preg-man-cy' weight.
THE POWER OF NAP
Keep your sleep debt down to keep the fat storing hormones low. It will be difficult to get long good quality sleep, so power naps of 20-40 mins where possible will keep you ticking over and help to keep your cortisol levels lower, preventing excessive weight gain.
FUEL UP
Keep meals full of nutrients to keep energy levels high. Each meal should contain a good protein source, some healthy fats and load up on bright colourful veggies. If time is really short, pre-prepared meat and veg can be a lifesaver.
SHORT & SWEET
Keep workouts short by trying high intensity interval training (HIIT) for maximum results. Just 20 minutes two or three times a week will maintain your fitness levels without taking you away from your pregnant partner or new baby for too long! You can try one of Fitness First's Freestyle HIIT classes for FREE! Visit their website for more information.
British dads-to-be are putting on weight during their partner's pregnancy