All of the following foods and drinks have been maligned or avoided out of concern that they cause weight gain or health problems. However, new research is indicating that these ‘enemy’ foods may not be so harmful after all. The key? It’s all about moderation, people!

The general consensus used to be that all fat is bad. In truth only some fats are bad (trans and saturated fats). Many others, such as monounsaturated and polyunsaturated fats, are good for us, if not essential. They protect our hearts, nourish our skin, aid metabolism and our ability to absorb fat-soluble vitamins, and help us feel full so we don’t overeat. This includes cooking oils – the healthiest being olive oil and coconut oil.

Yes, avocadoes are high in fat but it’s monounsaturated (good) fat. They’re bursting with nutrients, especially vitamins K and C, and eye-protecting antioxidants, and contain significant amounts of folate, potassium and fiber. Eating one for breakfast can also curb your appetite for the day.

Studies have shown that drinking modest amounts of beer, particularly ale, can lower the risk of stroke and heart disease. It’s also cholesterol-free, and contains cancer-and-dementia-fighting antioxidants and minerals such as iron and magnesium. Stick to lower-strength beer – it’s less calorific.

Bread has got a bad rap of late – cheap options are often highly processed, while low-carb diets such as Atkins reject it. But wholegrain or wholewheat bread provides us with much-needed fiber and nutrients from wheat germ such as Vitamin E and brain-and-heart-protecting Omega-3 fatty acids. Sourdough, on the other hand, is made using fermentation, the process of which makes bread easier to digest. It’s also good for gut health, and prevents blood sugar spikes. Aim for artisan or bakery bread.

Labeled as an adversary for decades butter – particularly grass-fed – is having a renaissance as studies show that its fatty acids can help weight loss and brain function. Present in butter is conjugated linoleic acid – an anti-carcinogen that also inhibits artery plaque and diabetes – and butyric acid, which fights cancer and aids gut health.

The fat content of cheese varies depending on the type but it’s generally regarded as being high in saturated fat. However, it also contains healthy monounsaturated fat and is one of the best dietary sources of calcium. Then there’s vitamins B1 and B2, selenium and zinc, all of which the body needs to function well, while aged and curd cheese are high in Vitamin K2, the so-called “missing link” between the Western diet and killer diseases.

Coconut oil used to scare people off with its high saturated fat content but the good news is that more than half of this is lauric acid, a medium-chain triglyceride that, when consumed, has been linked to raised HDL (good) cholesterol levels, reducing abdominal fat, and the easing of the symptoms of arthritis and other inflammatory conditions.

Coffee only becomes harmful when we drink too much of it or add too much to it, such as cream or sugar. It’s full of antioxidants and studies strongly indicate a link between coffee drinking and a lower risk of dementia, Type II diabetes and certain cancers. It’s best to drink 2-4 cups a day to reap the benefits (no more than two if pregnant or nursing), and don’t sup too close to bedtime as caffeine disrupts sleep.

Unless you’re lactose-intolerant there’s no need to give up cow’s milk. It’s a much better source of calcium, Vitamin D and protein than nut or rice milk and is especially important in children’s diets. Opt for small amounts of organic full-fat milk if possible as it contains higher levels of Omega-3 fatty acids that protect the heart and less – if any – chemicals, pesticides and antibiotics.

Not all chocolate was created equally – some varieties are laden with fat, sugar and cream, which makes it an unhealthy option. But good-quality dark chocolate has a higher percentage of cocoa in it, which is abundant in flavanoids, antioxidants that benefit the cardiovascular system, while the consumption of cocoa is linked to lower blood pressure and a reduction in stress hormones.

Once thought to be responsible for raising cholesterol in the body, eggs have been let off the hook since it was discovered that saturated and trans fat are the main culprits to affect cholesterol. Egg yolks contain the compounds lutein and zeaxanthin that help reduce the risk of age-related macular generation (eye disease), while it’s now largely accepted that eating eggs for breakfast satisfy appetite so we eat less during the day.

Ghee (clarified butter) is commonly used in Indian cooking but its reputation as a bad fat precedes it, which has hindered its use in other cuisines. In fact, if the ghee is made from grass-fed butter it offers the same benefits, namely two anti-carcinogenic fatty acids – conjugated linoleic acid and butyric acid. The former helps with weight loss and prevents artery plaque and diabetes while the latter aids gut health.

Raw nuts are a brilliant all-rounder but have a relatively high fat and calorie content. Some of the fat is saturated but nuts also contain heart-healthy monounsaturated fat and Omega-3 fatty acids, as well as fiber. Varieties serve different purposes: brazils are rich in thyroid-supporting selenium; almonds in skin-nourishing Vitamin E; pecans have antioxidant qualities; while hazelnuts are full of folate, which regulates homocysteine, an amino acid associated with heart and nerve problems.

Atkins and paleo diets reject the likes of pasta, but carbs play an essential role. The problem with pasta is not what it's made of but the amount we consume – a portion size should fit in the palm of your hand. That's about ½ cup. Yet we eat, on average, around two cups per serving. Stick to the right amount and include lots of vegetables, and eat fresh pasta where possible. It pays to cook it al dente too – firmer pasta has a lower Glycemic Index and isn’t so disruptive on blood sugar levels.

Nut butters, such as peanut butter, have a host of health benefits, though sticking to the serving size is recommended because of their high calorie content. But even a small amount is filling and can prevent overeating. To top it off peanut butter is a fantastic source of fiber, protein, muscle-friendly potassium, bone-friendly magnesium, skin-friendly Vitamin E, and hormone-friendly Vitamin B6.

Popcorn is a super-healthy wholegrain, an easy way to get fiber, and the hulls (the dark bits) are a surprising source of polyphenols, an antioxidant with numerous health benefits. Smother popcorn in salt, cheese, sugar or toffee and it is not your friend but there are better ways to serve this snack. Choose organic where possible, and opt for the air-popped variety with a sprinkling (rather than a downpour) of sea salt or butter.

Like pasta, starch-heavy potatoes have been vilified as a refined carb but it’s not the potatoes themselves that are bad for us but the ways we cook them. Potatoes are satiating and full of nutrients – they’re an excellent source of Vitamin C and potassium and contain resistant starch, which is a fat-burning carb, that’s especially prevalent when potatoes are cooked then eaten cold. Bake whole or in wedges with a small amount of olive oil or steam then add to salad.

Excessive consumption of red meat is linked to cancer, cardiovascular disease and diabetes, yet red meat is an excellent source of iron and the right kind (grass-fed) is a good source of heart-healthy Omega-3 fatty acids, conjugated linoleic acid, and Vitamin E. So don’t give it up if you love it, just eat smaller quantities – no more than 18oz of cooked red meat a week – and regard processed meat such as ham and bacon as an occasional treat.

Sugary and calorific is how wine is often described – two big negatives if your aim is to be healthy. But a small amount of red wine is recommended. This is because it contains a heart-protecting antioxidant, reservatrol, metabolism-boosting ellagic acid and piceatannol, a fat-preventing compound. Various studies, including one from Canada, found that moderate amounts of red wine (1-2 small glasses a day) reduces the risk of atherosclerotic disease. Pinot noir is especially good.

While red wine is regarded as the most beneficial alcohol small, regular amounts of other drinks may also help us. Moderate imbibing is linked to lower rates of diseases such as Alzheimer’s, Type II diabetes, heart disease and even certain cancers. However, pregnant or breastfeeding women, or people with an addictive personality, should avoid alcohol.

The high fat content puts weight watchers off salad dressings but the good news is that homemade dressings made with oil and vinegar not only have a sating effect, which curbs the desire to overeat, but the fat from the dressing helps our bodies absorb nutrients – such as carotenoids and lycopene – found in salad and vegetables. Choose an oil rich in monounsaturated fat such as olive oil and avoid shop-bought dressings as these can contain additives.

Once regarded as a starchy enemy white rice isn’t as naughty as we think (just ask the Japanese). It seems that the type of white rice we eat, the way we eat it, and what we eat it with makes all the difference. For example, long grain rice such as basmati has a lower Glycemic Index, while eating white rice al dente or with lean protein and veg lowers the GI. Brown rice is still regarded as more nutritious though it’s worth noting it has a higher arsenic content than white varieties.

Our obsession with lower-fat produce is changing as we realize that some fat is good for us and may even help us lose weight by filling us up and preventing us from gorging. One study found that normal weight people who ate full-fat yogurt were less likely to gain weight over time (yogurt is also good for gut bacteria, which is important for digestion and nutrient absorption). Overall, full-fat dairy – especially organic – is a valuable source of protein and calcium.