How to: drop a dress size in 21 days

Ditching a whole dress size in three weeks sounds too good to be true, but not impossible if you're one for liquid-only fasts and carb-banishing regimes

Personally, I like my food. Stick me on a heavily restricted diet and I turn nasty. Trust me, I've tried Atkins and gave in because I missed potatoes and pasta. I've tried the cabbage soup diet and only made it to day three which called for soup, skimmed milk and up to eight bananas – I rebelled with a huge tub of popcorn. And last but not least I tried living on cereal and apples (I was a student at the time) and was rewarded with bad skin, very little energy and a temper to rival Naomi Campbell.

All in all it's not a great dieting CV. In fact, having given up trying to follow any fad diets for the past eight years, I've been a much happier, healthier person. However, I'd got very lazy with my eating habits and my waist line was starting to expand, trousers were getting tighter and my muscle tone was next to nothing. I wasn't overweight, but I was a 'skinny fat person'. I looked slim enough with clothes on, but rather flabby round the belly, thighs and hips in the nude. My impending nuptials and honeymoon were enough to goad me into action.

The company promoting the 'Drop a dress size plan' Dax Moy Personal Training offered a money back guarantee that anyone can lose this much weight in 21 days if they stick to the diet and fitness regime. With 12 weeks to go before my wedding I was a very willing guinea pig.

Day one of the plan saw me hot-footing it over to the studios in Islington (London) to be measured, walked through the diet and exercise plan and given my Kinetic Chain Assessment (physical profiling) from which a series of corrective flexibility, balance and strength exercises were tailored to fit my body. For example, I have a dodgy shoulder so I was given plenty of strengthening exercises for those muscles.

It was pretty hardcore and my 'leaning' posture and poor stability were highlighted. I felt like a bit of a freak by the end of it, although I was assured that these were fairly common problems for someone who is primarily desk-bound all day. Phew!

The fitness programme

I met with a trainer, Katie Gormley, twice a week for the duration of the three weeks as well as following a series of exercises called Integrated Movement Training twice a day and doing the corrective exercises once a day. Each exercise programme is tailored to fit the individual – mine was a series of squats, twists, lunges, lifts and push-ups – and the focus is on resistance not cardio training. Dax believes that too much low intensity cardiovascular exercise causes muscle loss, which slows your metabolism – the last thing you need when you're trying to lose weight. Short, sharp bursts of activity are the way forward.