My husband is concerned that his wine intake may be damaging his liver. Are there any foods that can protect it? First, it is important for him to go for a check-up with his doctor to establish if any liver damage has already been caused and obviously to keep his wine consumption within the sensible drinking guidelines. For men, this is no more than 3 to 4 units a day. This is equivalent to just under two 175ml glasses of 12 per cent alcohol by volume (ABV) wine — less if it is a higher ABV. Most wines that you buy from supermarkets tell you the number of units per bottle and glass, which is helpful. A bottle of 12 per cent ABV wine will, incidentally, give him 9.6 units.

Milk thistle is often recommended for liver health. Medical herbalists believe that it helps to promote the growth of new liver cells and improve liver function. However, they say it is important to find versions that contain at least 70 per cent silymarin and to take 150mg three times a day.

Research suggests that green tea may also have a protective effect, probably because of its high content of the antioxidant EGCG, which is 100 times more powerful than vitamin C.

It is worth your husband ensuring that he also has foods rich in vitamin C, for example, papaya, guava, peppers, broccoli, berries and citrus fruits. Vitamin C is said to work with vitamin E found in wheatgerm oil, sunflower seeds, almonds, pine nuts, sweet potatoes and avocados to also to help to protect liver cells.

My 25-year-old son has been told that he needs to go on an egg-free diet. How does he do this?
First, who made this diagnosis? There are lots of “health” experts out there doing, quite frankly, dodgy tests that do not stand up to scientific scrutiny. Tests that are not recommended for detecting food allergy by the British Dietetic Association include hair analysis, IgG blood tests, kinesiology, the pulse and Vega tests.

If the diet has not been suggested by a qualified doctor after a medically supervised skin prick or RAST test, or by a registered dietitian after a referral from a doctor, he should talk his symptoms through with his GP before embarking on any diet that excludes eggs. If the diet is necessary, it is important that such a regime involves the total avoidance of eggs and foods that contain them, including the whole egg, dried eggs, egg yolk, egg albumin and egg lecithin. This basically means that some pasta, most biscuits, cakes, meringues and mayonnaise are out as well as many ready-meals and ready-made puddings.

The good news is that all pre-packed food in the UK that contains eggs or any of its derivatives must state this on the packet, which makes food shopping slightly easier. When eating out and buying food from sandwich bars, etc, your son must avoid things such as tuna mayonnaise sandwiches, muffins and, again, cakes and biscuits.

With home cooking, there is an excellent website, foodsmatter.com, that has some great egg-free recipes.

Does microwaving destroy nutrients? I keep hearing conflicting stories.
Microwaves cook by agitating water molecules in the outer 10 per cent of the food, creating heat that then travels inwards, cooking the rest of the food as it goes. They therefore cook, like most other methods, “from the outside in”, but are most similar to steaming.

As with steaming, little water is used, so water soluble nutrients such as vitamin C and the B vitamin folic acid do not get leached out and lost in cooking water. And because microwaving tends to be quicker than other methods, vitamins sensitive to heat, again such as vitamin C and folic acid, are well preserved.

In one set of tests comparing microwaving with boiling, the former has been found to preserve more than twice the vitamin C in vegetables, including broccoli, cauliflower and parsnips. In other research, grilling followed by microwaving and baking have been shown to produce the lowest losses of overall antioxidant activity of vegetables in everything from peppers and peas, courgettes, green beans and beetroot.

On the other hand, the health-boosting supernutrients called glucosinolates in broccoli appear to be adversely affected by microwaving and all cooking methods with the exception of steaming.

Nutrients such as protein and fat — along with minerals such as iron needed for energy, zinc for immunity and fertility and calcium for strong bones — are not much affected by any cooking method.

I work shifts and eat late at night. Does it make me more prone to weight gain?
Overall, it is the number of calories that you eat and the energy you expend that determine whether you lay down or burn off body fat. In theory it should not matter when you eat your calories over a 24-hour period as it is the balance of this equation that counts. But I have come across some interesting research, which was shown for the first time that feeding at the “wrong time” leads to weight gain in the experimental animals — in this case mice.

The scientists found that in their six-week study on 12 mice, although all were given the same calories within a high-fat diet, those that ate during the day gained twice as much weight as those fed at night time.

This would suggest that, if translated into people, maybe it would be a good idea to eat as lightly as possible during your night shift, while ensuring that you are well-hydrated with water, and saving your main meals to eat within normal daytime hours. However, it is probably worth planning your total 24-hour daily calorie intake and trying hard not to exceed it. Having snacks such as fruit rather than cakes, biscuits and chocolate if you start flagging during your shift is a good idea as the latter will cause your blood sugar to spike and then fall, leaving you hungry for more and feeling even more flaked out.

To read more of Amanda’s advice visit The Times Health Club at timesonline.co.uk/healthclub. You’ll find a further Q&A with her, and a fitness Q&A session with Matt Roberts.

If you have a nutrition question e-mail amanda.ursell@thetimes.co.uk

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