Anna Richardson and her no-nonsense team return to uncover the furtive foodies in a second series of Secret Eaters.
"The only reason anyone's overweight is because they take in too many calories, end of story," says the straight-talking Anna Richardson.
This is far from earth-shattering news, but the fact that many people won't accept this simple statement is the foundation of the popular TV programme Secret Eaters, which is returning for a second series with Richardson at the helm.
"It's really a show that looks at overweight people who simply cannot understand why they're fat," says the presenter.
"What I find fascinating is the level of their self-delusion, and I've been there myself because I'm a dieter, and I've struggled with my weight and thought, 'It's not my fault'."
Richardson, who began her career on The Big Breakfast and has since presented shows like Love Bite, You Are What You Eat and The Sex Education Show, believes most eating issues are psychological.
"About 99% of the time, it's got something to do with compulsive eating or bored eating or addictive eating, or just sheer denial about what's going on," she says. "Nine times out of 10, I'll hear people go, 'I don't eat enough to be this weight', or, 'It's not my fault, I've just had a baby'.
"A lot of people just can't accept it's because they eat too much - until you actually show them."
And that's exactly what happens, with the contributors' agreement, on Channel 4's Secret Eaters.
"We put hidden cameras in their house, get private investigators to get onto their tail to gather evidence of what they're eating outside the home, and we get friends and family to dob them in," explains 42-year-old Richardson.
After the team has gathered surveillance on the couples, siblings and friends who take part, the contributors are invited to London - "and then we hit them with our incident room," adds Richardson, laughing.
Within this room, they're faced with photos, footage and examples of all the food they've been consuming, without realising just how much it all adds up to. Often, the shock is hard to swallow.
"What we're doing is actually confronting people with the evidence of their secret eating," says Richardson. "You've got to remember, people go on this show because they literally have no idea why they're overweight, so when you confront somebody with it, the self-imposed veil falls from their eyes. That's the moment of change for them and that's absolutely crucial."
In the new series, the hidden cameras won't just be concentrating on the Secret Eaters' dietary downfalls.
This time the lenses will be zooming in on the public too - in all the places where we throw caution to the wind, like all-you-can-eat buffets or the office biscuit tin.
Richardson is aided in her task by chartered psychologist Dr David Lewis and dietician Lynne Garton, who will debunk the food industry's jargon and explain how our bodies can fool us into wanting more of the kind of foods that aren't good for us.
"Once you know the psychological triggers, you can do something about them," says Richardson, who's learned that most overweight people are mindless eaters.
"What tends to happen is that we eat in front of the telly or our computer or in front of our mobile phone, so we're constantly distracted by something else and not focusing on what's on the plate in front of us."
And there are some staggering facts from Garton pertaining to the individual contributors, she adds.
"It might be somebody who has sugar in their tea and she'll come out with amazing tips, like if they just dropped that sugar on a daily basis they could lose up to a stone a year.
"Just some small changes to your life can make a huge difference in terms of your weight and your health."
Once the contributors are aware of the scale of their over-eating, they then embark on a healthy eating regime to help them shift the pounds.
"We don't even call it a diet, we just suggest small changes," says Richardson. "Pretty much without question, they all say at the end of the process, 'I'm so grateful I've done this show because it really has changed my life'."
Richardson herself experienced a wake-up call while filming a series of Supersize Vs Superskinny.
"I was filmed doing all these diets and I had to get on some scales for the first time in seven years. I had my own Secret Eaters moment where I was faced with the fact I was a damn sight heavier than I thought I was," she says.
It's why the presenter notes that while Secret Eaters "is a sort of comedy-spy-diet show", the aim isn't to humiliate anyone.
"No one wants to laugh at overweight people because it's a huge issue, it's an epidemic in this country," she says. "I've been overweight myself and still struggle with my weight, so I hope the tone is absolutely bang on, which is 'Listen - I'm not a skinny person looking at you and thinking you're just a fat slob'.
"I'm looking at them going, 'I've been there, I understand this is difficult. We are here to affect change for you. We're on your side'."
Richardson has also written books and produced TV programmes relating to body issues.
"I think diet and food is a perennial subject, we'll never get bored of it, especially if you're a woman," she says. "In this country alone, the diet industry is a multi-billion pound industry therefore people are fascinated by food, they're fascinated by diet."
That goes some way to explaining the popularity of Secret Eaters. "But not only that, it's entertaining and it's quite tongue-in-cheek, so it's informative and funny and that's really what the best television should be," Richardson adds.
"The beauty of it is, whether you're a secret eater or not, you can identify a little bit with what's going on.
"People are going to sit there and go, 'Oh my God, that's me'!'"
EXTRA TIME - SECRET EATERS TITBITS
:: Studies show we make more than 200 decisions a day over food and most of them are unconscious.
:: We eat with our eyes, so when we see certain food we are tempted to eat it even if we're not hungry.
:: The 'Serial Snacker' opts first for a satisfying savoury snack but then craves a sugar high, an addictive cycle which overloads the taste buds.
:: Beware the health 'Halo Trap'. Dieters who go for low-fat labels are 21% more likely to allow themselves calorie-laden extras.
:: The 'Double Diner' goes back for second helpings and has extra meals throughout the day. These people should eat food that keeps them feeling fuller for longer, increase the amount of salad or veg with meals, and eat fruit or nuts in between meals if they're still hungry.
:: The second series of Secret Eaters begins on Channel 4 on Thursday, March 28