Dietetic dogma tells us that we should eat three meals a day, but resist the urge to feed our faces with anything else in between. Like doner kebabs and deep-fried Mars Bars, snacking is something that the nutritional fraternity tends to frown upon. Despite its sullied reputation, recent evidence suggests that eating between meals mightn't be such a bad idea. A study published in the British Medical Journal found that frequent feeding was associated with lower levels of cholesterol in the bloodstream. This, despite the fact that the snackers tended to consume greater quantities of fat than their more restrained counterparts. As it happens, this is not the only piece of research which points to snacking as a healthy way of eating. Several studies suggest that frequent feeding has a range of beneficial effects on health and well-being.

The idea that eating between meals is bad for us is rooted in the belief that it only serves to up our intake of calories. Keen to do what we can to keep surplus pounds at bay, many of us tend to confine ourselves to two or three fuellings during the day. Generally speaking, however, the less frequently we eat, the more we tend to eat when we do. The problem is that big meals can tend to upset our internal chemistry, and pose significant hazards for us in the long term.

The main imbalance induced by large meals concerns the levels of sugar and the hormone insulin in the blood stream. After eating, blood-sugar levels tend to rise. In response, the body secretes insulin which helps bring blood-sugar levels back to normal. However, while insulin performs this critical role in the body, too much of it can be a bad thing. Another of insulin's effects is to stimulate the conversion of sugar into fat, which can easily manifest itself as excess body baggage. Insulin also encourages the liver to manufacture cholesterol and other blood fats called triglycerides, both of which have been fingered as risk factors for heart disease and stroke. All this means that, the bigger a meal is, the more likely the body is to generate what amounts to self-made suet.

There's no doubt about it; big meals can mean big trouble for the body. By evening out sugar and insulin levels, snacking should reduce the amount of artery-clogging and supplemental fat we produce. More importantly, the theoretical benefits of regular eating do indeed seem to translate to tangible benefits in practice. In one study dating back to the mid-60s, eating more regularly was found to be associated with not just lower cholesterol levels, but lower body weight, too. Half of individuals eating three meals a day or less were found to be suffering from high cholesterol, compared to only 20 per cent of those eating five or more times each day. Also, more than half of the first gorging group were found to be overweight, compared to less than a third of those eating more frequently. Another study examined the relationship between eating patterns and heart disease.

Frequently eating appeared to reduce heart disease risk by about a third.

In recent years, nutrition researchers have gone on to examine what effect changing the way we eat, rather that what we eat has on health. One study measured cholesterol levels in individuals eating three meals a day. When these individuals were fed exactly the same food as just one meal each day, their cholesterol levels went up. The same food fed as 10 meals a day, on the other hand, caused cholesterol levels to fall.

Other studies have shown that grazing not only helps keep cholesterol in check, but can also reduce the levels of other potentially hazardous substances, such as sugar, insulin, triglycerides and the stress hormone cortisol. The message is clear: eating less but more frequently offers significant health benefits for the body.

While snacking does appear to do us some good, the benefits will obviously depend on what we eat (as well as when). In my opinion, an ideal snack would be some fresh fruit or vegetables coupled with some nuts or seeds. Fruit and veg provide the body with high-quality, nutritious and fibre-filled carbohydrate, while the nuts and seeds provide both beneficial fats and protein. An apple and a fistful of cashew nuts or some raw carrots and pumpkin seeds make fabulous mid-morning or late-afternoon snacks. Eat them safe in the knowledge that it really is better to graze than to gorge.

Dear John...

My husband is 69, plays tennis and golf, but also needs to take anti-inflammatories for joint pain. Is there anything that can be done to protect our joints?
Margaret Hickling, Altrincham

The most common form of arthritis as we age is caused by wear and tear to the smooth, shock-absorbing cartilage that lines the joints. The medical term for this condition is osteoarthritis, the treatment for which is centred on the use of non-steroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen. While these drugs may help control joint pain, there is also evidence that they speed the rate at which joints degenerate.

There are two natural agents that seem very effective in helping to protect against and even healing problems with osteoarthritis. One, glucosamine sulphate, is essential in the manufacture of cartilage tissue. The other, chondroitin sulphate, helps maintain cartilage health by improving the delivery of nutrients to cartilage tissue. Several studies show that both glucosamine and chondroitin sulphate are safe and effective treatments.

Because these treatments help to heal damaged tissue rather than merely quelling pain, their benefits may take some weeks to become apparent. The recommended doses for full-blown osteoarthritis are 500mg of glucosamine sulphate, and 400mg of chondroitin sulphate, each taken three times a day. However, as your husband sounds not too badly affected, he may benefit from once- or twice-a-day dosing.

· If you have any issues you would like Dr John Briffa to address in this column, please contact him by email on life@observer.co.uk. Please note that Dr Briffa cannot enter into any personal correspondence.