How to lose weight: Forget diet fads, eat less and move more

You've been dieting for two weeks, determined to squeeze into your little black party dress. You've avoided sugar, carbs and bad fats. You're all about superfoods and supergreens and are on first-name terms with the staff at your local health shop. You feel awesome. But you are not losing weight.

We now bandy around buzzwords like paleo, clean and organic, while discussing the merits of cutting out grains, dairy or gluten. Or all three. We snack on protein bars or refinedsugar-free flapjacks instead of chocolate, and choose oven-popped vegetable chips over packets of bog-standard salt 'n' vinegar.

Then why are we not morphing into Greek gods? As a nation, we're getting fatter. According to Public Health England, 64 per cent of adults are overweight or obese. I am one of the healthy brigade who was mystified as the counter crept up on the scales. I had replaced re-fined sugar with agave, maple syrup or honey, and white flour with almond flour. My beef was grass-fed, my butter and eggs organic, and nutbased bars were my snack of choice.

It took an awfully long time for the simple truth to dawn on me. Calories do count. While some food fads exhort you to ditch the scales and stop counting calories, they don't encourage you to eat like you're preparing for hibernation. We added that little footnote ourselves. Weight-loss expert Louise Parker has seen every ''diet footnote'' in the book. "The most common mistake that we see is over-consumption of calories, coupled with inactivity," she says.

"What is more surprising is that clients will fall into two categories - those who realise they are overeating and not active enough and those who really think they are and are baffled, citing a 'poor metabolism' or 'bad genes'.'' Calories can be difficult to count in homebaked creations, but shop-bought alternatives can be awash with other perils. Companies have cottoned on to ''clean'' eating and suddenly the word ''natural'' is emblazoned on everything. Beware: technically salt and sugar are natural, as are plenty of other nasties that will be tougher to digest and harder on your body than the stuff they're replacing.

Healthy snack bars can have as much sugar as a Snickers. One popular green juice on supermarket shelves clocks in at a whopping 53.5 grams of sugar (the WHO daily recommendation is an average of 25g). Even Coca-Cola has jumped on the bandwagon with Coca-Cola Life - which has a green label and natural stevia flavouring (and 22g of sugar per can).

But what of the glowing goddesses touting their food-porn on Instagram? Enter the #eatclean hashtag and you'll be greeted with an array of bronzed six-packs, chia porridges, vats of green juice and stacks of pancakes. Surely the paleo posse are doing something right? "Instagram is awash with skinny girls posting coconut porridge with caramelised prunes and pistachio nuts," says Parker.

"Delicious - yes, but calories-wise it's a match for my mother's sticky toffee pudding and not best consumed for breakfast if your goal is to look like the girl in the picture. What you can't see is that perhaps she doesn't eat it, or she works as a personal trainer for eight hours a day."

So should we just reach for the takeaway menu? Well, no, not quite. Make smart, informed choices of what you put into your body - and how much. "The trick is to eat whole, real, seasonal, nutritious food," says Parker. "So choosing organic, natural options is already a great move in the right direction - but the sugar and calorie content has to be balanced in a way that stabilises your blood sugar levels, whilst boosting you with nutrients."