Go jogging

Good news: we all have an ironing-board stomach. Bad news: more often than not it is hidden beneath at least one layer of fat. To find it, start by increasing the amount of fat-burning aerobic activity you do. That will lower your body fat levels so you can see the muscles you are trying to work, says Louise Sutton, principal lecturer in health and exercise science at Leeds Metropolitan University. "Aerobic exercise such as running, swimming or rowing raises metabolism during and after the activity, making it less likely that calories will be stored around the abdominal area, or anywhere else, as fat," Sutton says.

Don't starve yourself

While a healthy, low-fat diet is important for reducing body fat and flattening your stomach, eating too little can backfire, with disastrous consequences for your midriff. According to personal trainer Kevin Barclay-Webb, whose clients include Annie Lennox and Ivana Trump, cutting calories too drastically "increases the production of the stress hormone cortisol and insulin, which controls blood-sugar levels". Consequently, he says, "the body responds by storing excess calories in the abdominal region". Mostly the calories are stored as fat - "which is why otherwise very thin people can still have a roly-poly belly".

Ditch the gadgets

A study by researchers at Kansas State University found that gadgets that promise a flat stomach with regular use might not be worth the money. The study, published last year in the Journal Of Athletic Training, involved 23 men and women using various devices, while electrodes measured the stimulation to their abdominal muscles. On average, the products elicited no greater muscle activity than traditional sit-ups. Two of the pieces of equipment, an ab slide and a fitness ball, caused more activity in the hip flexors than in the stomach - "an undesirable feature of abdominal exercises", the researchers concluded.

Laugh yourself flatter

Warwick McNeill, a chartered physiotherapist based at the Physioworks clinic in London, says that strengthening one muscle above all others - the transverse abdominus - has the greatest bearing on flattening the midriff. Because it is so deeply embedded, however, it is difficult to isolate. "A lot of fitness activities, like aerobics, don't work the abdominal area effectively," McNeill says. "The real key to strengthening the transverse abdominus muscle lies in very subtle movements. Laughing is ideal, because it contracts the muscle appropriately."

Improve your posture

A lot of gym-goers have round shoulders as a result of training programmes that over-concentrate on the chest and shoulders. But you can look instantly slimmer just by altering the way you stand. "Standing up straight can have an instant stomach-flattening effect," says physiotherapist Sammy Margo, a spokesperson for the Chartered Society of Physiotherapy. "Maintain the natural curves of the spine, watching for exaggerated arching in the back, which could push the abdominals forward, creating a rounded tummy. Lengthen up through your spine and don't slump."

Try Pilates

The abdominals act like a corset for the internal organs, so it is not just the muscles at the front that need to be toned, says Pilates instructor Jo Tuffrey. "For a strong, well-toned midriff, you need to condition the external oblique muscles that run down the sides, the internal obliques that allow you to bend and twist and the deep transverse abdominus that circles the body like a belt," she says. "Repetitive exercises like sit-ups and crunches can do more harm than good, because they work only one area. The result could be that the strong muscles tighten, leaving the waist looking thicker. Pilates tackles the whole works, helping to develop a strong centre to the body by recruiting all muscles to lengthen, strengthen and stretch them into shape."

Watch what you eat

Chewing gum is a particular enemy of those determined to avoid the pot-bellied pig look. Researchers at the American College of Gastroenterology found that it makes you swallow a lot of air, which inflates the belly until it is expelled. Smokers and fast talkers have the same problem. There are some dietary factors that contribute to a bloated stomach that can be addressed immediately. "Try to eat light foods such as salads and fish if you want a flat stomach for a party or special occasion," says Sutton. "They are easy to digest and will help to avoid a build-up of intestinal gases." Drinking plenty of water will also help you avoid fluid retention.