Eat more and more, do you know chemicals in foods blow you appetite?

In a very real sense, everybody has direct reactions to foods. Direct reactions are reactions caused directly to cells by chemicals in foods. Among the most obvious direct reactions are those caused by alcohol. If you drink alcohol, you are almost certain to experience sedative effects, due to the direct effect of alcohol on your brain cells.

Often, people with Asian heritage react quite negatively to alcohol, and the common belief is that they're allergic to it. Technically, though, they don't have an allergy; they have a sensitivity — because this is a direct reaction, which doesn't involve the immune system. I believe that it's clearer and more sensible to say simply that Asians often have a food reaction to alcohol, since food reactions include both allergies and sensitivities.

Direct reactions, however, can eventually involve the immune system, because sooner or later the immune system is called in to repair the mess that direct food reactions cause. Therefore, the symptoms of direct reactions can feel much like allergies. Because of this, direct food reactions are sometimes called false food allergies.

Alcohol has obvious direct actions, but most direct food reactions are more subtle. Often, direct reactions occur when chemicals in foods bind with the cells that produce histamine; these cells are called mast cells. When this happens, it can cause the release of histamine. The food chemicals that are most likely to do this are lectins, which are most often found in wheat, peanuts, and beans. Another cause can be certain partial proteins, or peptides, that are found in tomatoes, strawberries, shellfish, pork, chocolate, and eggs.

Other foods that often seem to cause direct food reactions are mustard, pineapple, papaya, buckwheat, and sunflower seeds. Ironically, one patient of mine had terrible digestive symptoms, including severe heartburn, and took large amounts of digestive enzymes to help the problem. However, his enzymes were full of papaya, which he later found he was reactive to. When he stopped taking the digestive aids, his digestion improved immeasurably. Moral of the story: don't trust common knowledge about what's healthy — trust your own experiences. Everyone is different.

Other foods that sometimes cause direct reactions are those that contain high levels of natural histamines. Histamines are formed in foods that are allowed to age and ferment. Therefore, histamines are often found in aged cheese, sausage, and salami.

Other foods that can cause direct reactions are those that contain the partial proteins tyramine, phenylethylamine, and octopamine. These chemicals, like histamines, can cause blood vessels to expand and contract, which causes tissue swelling. In the head, blood vessel constriction and expansion can cause migraine headaches. That's why people who get migraines often shun the foods that are high in these partial proteins, such as wine, aged cheese, citrus fruit and yeast.

Another common foodstuff that often causes direct reactions is the artificial sweetener aspartame. Aspartame is mostly composed of the partial protein, or amino acid, called phenylalanine. In some people, it acts directly on brain cells, causing symptoms such as agitation and depression. In other people, it causes blood vessels to contract and expand, triggering migraines. In most people, though, it causes no reaction at all.

Many people also react to MSG, or monosodium glutamate, with headaches, nausea, dizziness, heart palpitations, and confusion. Others react to various additives, including nitrates, sulphites, and artificial food colours.

Another name for direct food reactions is pharmacologic reactions. That's a good description, because it implies an important point: foods, like drugs, are chemicals. Not all drugs are good for you — and not all foods are, either.

Now let's look at the last type of food reaction: immune complex reactions. This type of reaction is not well known. But it should be. It can be a killer.

Foods, like drugs, are chemicals. Not all drugs are good for you, and not all foods are, either.

Food still has it all!

We are often given warnings, especially by some companies that sell the 'milkshake' diets, that our food is toxic and poor in nutrient content. They imply that we will all be much better off drinking their shakes rather than eating what Mother Nature has to offer. Ha!

But then on the other hand, some food purists are forecasting that we are all going to develop all sorts of cancers and ambiguous genitalia because of all the chemicals in our foods. They stress that 'organic' is the only way to live. Well, that would be more than excellent, but organically grown produce is not always within reach of all of us, so what now?

Now we face reality. The truth is that not all chemicals and food additives are harmful. Some serve a very useful purpose. Another truth is that, although most producers use pesticides and chemicals in varying degrees, there are still more than sufficient levels of nutrients in fresh or frozen produce to justify their daily consumption! In fact, while the war between producers and food purists continues to rage, scientists have concluded that any potential risk from chemical residues is still outweighed by the benefit of the reduction in chronic diseases and nutrient deficiencies when adequate amounts of fruit and vegetables are consumed.

Avoiding foods for fear of consuming artificial chemicals will definitely result in a high-protein diet, as well as a diet high in fatly, sugary foods. The inevitable conclusion of such a diet is obesity and the resultant long-term diseases related to it, as well as malnutrition. Besides, sugar, starch and meat products are not free from added chemicals. So there, Eat your fresh produce!

Salads: sink or swim

Salads don't guarantee leanness. You can and probably often do, go right over the top with what goes into your salads. Again, establish beforehand what your intention is when you want to eat a salad: is it to be a meal on its own, an addition to the main course or a starter?

Most salad ingredients offer abundant nutrition and very few kilojoules. A large, 100 g pack of lettuce leaves contains a humble 67 kilojoules. Other green vegetables such as baby marrow, green pepper, cucumber and broccoli contain (on average) around 100 kilojoules per 100 g. Thus, enjoying a medium-sized salad bowl filled with a salad made of these ingredients, dressed with an oil-free dressing, will provide you with no more than about 140 kilojoules. This is a real bargain in the healthy slimming stakes. But go one further and dress the salad with two tablespoons of a simple, basic vinaigrette (oil and vinegar) dressing. Instantly you have 'bulked out' your salad with an additional 840 kilojoules - kilojoules you cannot taste as you would taste say a slice of rye bread or a baked potato (that you could enjoy with your salad), and kilojoules that cannot make you feel any fuller.

The plot thickens more when you take the sink-or-swim decision to add delicacies to your salad: cheese, meat, eggs, oily fish and olives. When you want to add any or all of these delicacies, go light on the dressing. Use an oil-free dressing. Furthermore, regard this kind of all-in-one salad as a meal rather than an addition to your meal. In that way you will balance the scales and not experience that sinking feeling when you weigh yourself the following day and find that you have consumed far-far more fat kilojoules than you were aware of. Even a simple, mixed vegetable salad, if dressed heavily with an oily or creamy dressing, will cause your kilojoule intake to soar and your once-crisp, fresh salads to be drowned in fat limp and unappetising.

The bottom line is this: if you choose to have something light such as a salad, keep it light.

Desserts: the big guilt trip

Desserts tend to evoke more feelings of guilt than any other item on the menu. And we know the reason why: most desserts are laden with fat and/or sugar and dessert is not really necessary to satisfy the appetite. It is the proverbial 'cherry on the cake'. Many of us have the mindset that we are only entitled to dessert if we have been 'good'. And very few of us ever feel that we have been 'good', because we feel that being overweight is already a symptom of being 'bad'. So we don't really feel entitled to it, but we have it anyway; it's irresistible; we are addicted to sugar. Then we feel bad about having had it and the guilt trip sets in, a guilt trip that can only be alleviated by some chocolate. By then we feel we are in so deep already that we might as well go all the way - another example of the vicious obesity cycle in full motion!

Follow a few simple rules about dessert and banish the guilt.

• Regard dessert is part of the menu, not 'over and above' it. Then, plan your menu accordingly, bearing in mind that the sugar and fat content of the dessert must make up part of the total intake of fats and carbos of the meal. In this way you will create the correct balance.

• Trade in sugar for fruit. Many fruits offer an abundance of natural sweetness, reducing the need for extra sugar in the recipe.
• If your recipe requires sugar, go for fructose. It is a natural fruit sugar with a very slow GI, thus keeping your blood sugar levels more even and thus preventing a further sweet craving later on.
• Trade in cream for yoghurt. Even Greek yoghurt contains much less fat (and therefore kilojoules) than cream. It also tastes cool and refreshing on the palate, ideal after any meal.
• Trade in ice cream for frozen yoghurt or sorbet. The fat content and therefore the kilojoule content is much less.
• Bear balance in mind. A heavy meal warrants a very light dessert - such as sorbet or fruit salad with yoghurt - and a light meal might justify the enjoyment of a small portion of richness - such as cheesecake or chocolate mousse.
• Don't have an all-or-nothing approach. It leads to a feeling of being deprived and that leads to bingeing. Have some - but just a little - and enjoy it without any guilt. Remember, guilt trips could cause hunger pains!