Despite being one of the most desired men in the country, it's no secret that Gary has struggled with his weight since his rise to fame in 1990, as the lead singer of infamous boy band Take That.
Although he's in the best shape of his life now, Gary has revealed his weight still keeps him up at night after admitting being 'fat' again is his 'greatest fear'.
Speaking in a recent interview with BBC Good Food magazine, the 46-year-old star explained that a dark time in his life pushed him to become overweight.
'My greatest fear is going back to where I was in 2002, when I didn't have a record deal and I was very fat.
'I don't want to use the F-word but I am going to have to, because I was. So Dawn and I are pretty strict with our own eating.'
Originally cruelly labelled as 'the fat one' of the band, Gary admits he's tried every diet out there and constantly battled fluctuating weight, struggling to maintain a healthy balance.
But keen Twitter followers of Gary's will notice that he's been showing a huge enthusiasm for keeping fit and healthy recently, which has led to an incredible overall weight loss of five stone since he began his slimming journey. It's even given him a boost of confidence to do a shirtless scene for his new show Let It Shine.
Left: Gary pictured in November 2005 promoting a reunion tour. Right: March 2017 at a film premiere.
Knowing he was going to be topless on TV, Gary forced himself to reassess his life, telling The Sun: 'I'm gonna get in shape for this. I wanted to get semi-decent. I didn't want the moobs flopping away there'.
But how did he do it? We look at Gary's methods and must-dos to see how he achieved his weight loss and healthy attitude - and to see whether we can replicate it ourselves!
Batch cook meals and take them to work with you
Gary loves to experiment in the kitchen, and just like us mere mortals, the international star has a habit of taking leftovers to work.
Speaking to BBC Good Food magazine, the singer revealed he's partial to spending some time in the kitchen the night before to whip up something healthy and homemade so that it's all ready to take with him the next day, stopping him snacking on something naughtier when he's out and about.
'At the moment we are loving Persian and Thai food. I often do a Thai fish curry. I know the basics and I make it up as I go along, and often cook one a day in advance. A curry always tastes better the next day and, because I'm out all day working, I cook stuff to take with me.'
Start every day with a hot water and lemon
Not only is hydration really important for a healthy body, helping you flush out toxins and aid weight loss in itself, but you can take it one step further and start every day with a hot water and lemon - just like Gary.
Gary swears by this method for starting off his day and it's a great routine to get into. Drinking warm water with lemon aids digestion, cleanses your system and helps to starve off naughty hunger cravings for the rest of the day. Also, by starting your day right, physiologically you're less likely to want to ruin your healthy streak.
Get into yoga
When someone suggests being more active, we completely feel your fear when you imagine yourself a breathless, beetroot red, sweaty mess and think 'I'd rather not!'. But doing more exercise doesn't always mean throwing yourself onto the treadmill - you can ease your way in with something a lot more relaxing, like yoga.
Gary regularly tweets about his time doing yoga, something he's developed a passion for as it helps his mind as well as his body. Yoga is great for core strength, as it helps with toning up and feeling good about your body. Try a beginner's class - if anything it's some quiet time away from the kids!
Go on a walk - or hike!
If you're an outdoor enthusiast like our Gary, hiking could be the secret to your weight loss success. But, if you're not feeling quite that brave and possibly don't have some 12k hiking routes casually dotted around your local area, walking is a great place to start.
Walking seems like an easy option, but it's incredibly good for you, toning your legs and bum like no other. If you don't fancy going on a hiking holiday, incorporating more walking into your day is a manageable change you can make to your life that will make a difference. Try promising yourself to take the stairs instead of the lift and walking to a further away bus stop to start things off.
Have a good breakfast
Hello !!!! pic.twitter.com/y1yqvqqgMO— Gary Barlow (@GaryBarlow) January 2, 2017
Starting off your day with a good breakfast is essential, and for top meal tips Gary's Twitter feed is full of them!
To take a leaf out of Gary's book try grilled mushrooms, courgette and a poached or fried egg cooked in low calorie spray. Other favourites of the singer appear to include porridge soaked overnight in almond milk and brown bread with mashed avocado, seeds and poached eggs as a topping, both of which he's shared snaps of on social media recently.
Remember to treat yourself after a hard week
Cheers ! What a week !!! pic.twitter.com/hNNcS3n4At— Gary Barlow (@GaryBarlow) September 24, 2016
Gary might be all about the healthy lifestyle, but he knows when he deserves a treat!
Although it's commendable to stick rigidly to a healthy eating plan, and when cutting out addictive sugary foods it's important to stay on track, there is the danger that by being too strict you could end up binging.
If you know you have a tendency to pig out after being disciplined for a while make sure you're not too hard on yourself, and treat yourself when you deserve it. If that means a glass of beer or wine at the end of the week - then we think you deserve it!