We know the way to lose weight and keep it off is to eat right, exercise more and keep this up for, you know, ever. Easy to say, not so easy to do. But science is on our side. With obesity raising its treble-chinned head as one of our biggest health concerns, research on weight loss is booming. So we looked at recent studies on successful strategies - from the glaringly obvious to the more left-of-centre - to see if they work in a non-lab setting.

Emails can help you eat better and exercise more

Talk to any behavioural scientist (you know one, right?) and they'll tell you that to change behaviour, you need to set small, individually tailored goals, and track them. We can all promise we'll walk more and eat less pad thai; it's sticking to said small goals that's the problem. Which is where email comes in, says a study in the June issue of the American Journal of Preventive Medicine. Researchers assigned 351 US office workers to receive weekly emails and mid-week reminders with "small step goals" like walking at lunch, or eating fruit as a snack three times a week. Another 436 subjects didn't receive emails. After 16 weeks, the email group were more likely to walk more, eat more fruit and veg and less saturated and trans fats than the control group. The most impressive changes were in people who, at the start, weren't meeting recommended dietary and activity levels. Their moderate activity increased by about an hour a week, compared with those who didn't get emails, and time spent on sedentary activities dropped two hours a week. Researcher Dr Barbara Sternfeld says it works because it's convenient and easy: "People realised that, 'Oh, I can do this...' And our data shows, at least four months later, the behaviours were still sticking."

Alison signed up to hassleme.co.uk for a week

THE GOOD
"It's pretty simple and a nifty idea. You sign up to be nagged about a topic of your choice (go to the gym, drink a glass of water, raise a people's army and seize control of the state) and they send you reminder emails at "semi-unpredictable intervals". Because I didn't know when the emails were going to arrive, they were more likely to get my attention. Good for people who work in front of a computer all day."
THE BAD
"My mum could win gold at the nagging Olympics, so I'm fairly impervious to pestering. And emails are easy to ignore (and delete), especially when you're flat out at work."
THE VERDICT
"I didn't lose any weight to speak of, and I didn't go to the gym any more than I normally would. But I did feel guiltier about it when I couldn't go - does that count?"

Photographing your food cuts kJs (aka the Flash Diet)

Our stomachs are bigger than our eyes, says research by Cornell University in the US, which found we underestimate how many kilojoules we consume by as much as 38 per cent. This is why food journalling is such a useful weight-management tool - it helps minimise self-deception. But the realisation that you ate waaay too many chips at the pub isn't so useful at the end of the day when you've already eaten them. So researchers from the University of Wisconsin-Madison in the US asked 43 self-described healthy eaters to photograph every meal, snack and drink that passed their lips for a week (they also kept a written diary). Lead researcher Dr Lydia Zepeda theorised that the act of taking a pic would make people more aware of what they were eating in the moment - and motivate them to change their mind. Sure enough, when the subjects reviewed their photo-diary, they found their portion sizes were too big, snack choices were kilojoule-heavy and fruit and veg only made a fleeting appearance. "I had to think more carefully about what I was going to eat because I had to take a picture of it," one participant told the researchers. "It curbed my choices. It didn't alter them completely, but who wants to take a photo of a jumbo bag of M&Ms?" Point well made.

Hanna got snap-happy for a week

THE GOOD
"I've tried almost every diet known to Oprah, including keeping a food diary. The best bit about the Flash Diet is it's quick - it only takes a second to snap your food. I eat the same breakfast (porridge) and lunch (tuna/avocado/cheese on ricecakes) every day, so it was easy. I referred to the same pics every time I felt like inhaling Green & Black's Maya Gold. That I didn't want photographic evidence of."
THE BAD
"Whipping out your phone at dinner with friends is rude enough, but explaining it's part of your eating plan? Embarrassing."
THE VERDICT
"I lost 1.5kg while following this. But I also had gastro briefly, so while I can't quantify the effectiveness of photographing what you eat, I can say it's a great visual aid, and you'll avoid stopping at the lolly jar in the office because you can't be arsed to take a pic."

Bite size and chewing time makes a difference

OK, so as weight loss revelations go, this ranks up there with "ask for dressing on the side" in the heard-it-3497-times-before stakes. Yet research is still being done into optimal chewing times and bite size. And who are we to argue with the whitecoats? A recent study in the American Journal of Clinical Nutrition confirmed that smaller bites and longer chewing times led to decreased food intake in the 22 normal-weight people studied. The Dutch researchers tested subjects seven separate times under different conditions to see how much custard they could eat until they were full. First, they could take a "free" bite size and eat it at any pace they wanted. Then, chewing time and bite size were varied (three seconds and nine seconds; and 5g and 15g respectively). When the longer chewing time was paired with the smallest bite size, the average custard intake was 313g - compared to 476g when eaters took bigger bites and had it in their mouth for less time. Obvious? Maybe. Difficult to chew custard? Undoubtedly. But by eating 163g less, the participants saved themselves around 685kJ. Having food in your mouth for longer, say the researchers, means you have "greater oral sensory exposure" to it, resulting in significantly reduced food intake. Fair enough.

Emma nibbled (slowly) for a week

THE GOOD
"This trial was clearly intended for people like me. I hoover meals down and scout for seconds while others are still halfway through firsts. I was surprised I didn't find it boring to chew for so long - in fact, counting nine seconds for each bite was vaguely meditative. Where it really came into its own was whenever I ate out. At a wedding, when the canapé tray came round, my friend wolfed down two sausages and a battered prawn to my one salmon blini."
THE BAD "This doesn't work for liquid kJs. Holding beer in my mouth for nine seconds was an exercise in stupidity, not weight loss. And the hardest thing was remembering to do it."
THE VERDICT "At the end of the week I'd lost half a kilo, though this could have been due to being on holiday and walking more. I'll definitely keep it up, though - it's easy and effective."