Start your plan with a big clear-out. Help rid not only your cupboards but also your body of unwanted substances that hinder the skin – and make a fresh start. Stock-up on the more internally cleansing ingredients, such as green leafy veggies, fresh ginger root and plain live yoghurt. Invest in a water filter jug if you don’t already have one and be prepared to enjoy some new foods.

This week you may like to get your day off to a skin-saving start with my Cinnamon-toasted Oats with Yoghurt and Summer Fruit. Swapping out the more usual pasta and potato carbs for a skin-friendly low-GL lentil dish is also a good option. My Lentils with Rainbow Vegetables and Kale Pesto are simply sensational!

Inside: Detox your fridge and food cupboards, and make smart swaps

Our skin mirrors the condition of our body on the inside. All the great creams and potions in the world won’t make you truly radiant if your diet isn’t also skin friendly, so looking at what we eat is the first step in our six weeks to great skin.

Most of us know how to eat healthily – there is so much good advice around nowadays – but it’s all too easy to let bad habits build up. Many processed foods, for example, contain too much sugar and salt, as well as synthetic colourings and other unhelpful additives. We’re not likely to take in enough of these to do us serious harm, but it’s not hard to see how our bodies can get overloaded – and this can show up on our faces as dull, dingy skin.

It’s good to go right back to basics, cutting out processed foods as far as possible and eating fresh food that’s had as little done to it as possible. Even apparently healthy fruit and veg may be coated with pesticides and fungicides, so give them a good scrub in soapy water and rinse and dry well before using. Consider buying organic produce if you can – farm box delivery schemes are handy, and usually good value.

Start your ‘detox’ week by clearing out your fridge and food cupboards. If biscuits, cakes and processed stuff aren’t readily to hand, you’re not going to be so tempted. Instead, make sure you’re well stocked with fresh, nourishing foods, such as whole grains (short-grain brown rice is one of my favourites), seasonal vegetables and fruit, as well as nuts and seeds and other healthy snacks. I certainly don’t want to encourage waste, but this is also a good time to get rid of any stale herbs and spices that won’t do your cooking or your body any favours, as well as those long-forgotten, almost empty jars at the back of the fridge. Chuck out anything that doesn’t smell right. Check dates on foods such as pulses and nuts (they can go stale and rancid, especially if they get too warm) and make sure you move those that need using soonest to the front of the shelf.

Audit your freezer, too, and check packaging and labels. Cook anything that needs using up, and compost foods that are spoiled.

SMART SWAPS

• Finish up any cereal, and re-stock with porridge oats instead. Consider making your own muesli, which is likely to be much healthier than anything you can buy ready-made.
• Stop buying flavoured yoghurts and go for live natural yoghurt instead. You can also try to make your own.
• Cut out the crisps. If you fancy something crispy without the calories, try thinly slicing a bagel and baking until crisp. These make good low-fat crispy bites (or use them for dips). Stock up with nuts as well as sunflower and pumpkin seeds. Try making some of my beauty bombs to snack on.
• Fill your shelves with lentils and other pulses, dried or in cans. Make sure you have stocks of the more unusual healthy grains such as quinoa and freekeh, both great for quick, sustaining, skin-friendly meals.
• Try spelt flour instead of plain white, and go for spelt or buckwheat pasta or noodles. They provide slow-release energy instead of insulin-surging sugar spikes.
• Avoid shop-bought dressings and sauces and go for good natural oils, such as olive, nut and avocado – all great for the skin, and some of my favourite internal skin-plumpers.

Outside: Detox bathroom cupboards and your make-up bag, too

This is a good moment to have a long hard look at your bathroom cupboards and make-up stocks. It’s not a good idea to overload our skin with lots of different products, so find what suits you and stick to it. I’ve used the same three-step Cleanse, Tone and Moisturise regime for over 20 years.

Inevitably, our shelves tend to get filled with impulse buys, samples and unwanted gifts, so have a good sort out. Give away anything you don’t like or will never use. Check use-by dates and throw away any products that smell bad. Most products have an open-lid icon with 6M, 12M or 18M printed on the base, indicating how many months these can be kept after opening. Wash your make-up brushes and bags using shampoo.

Mascara and lipsticks can harbour bacteria from our eyes and mouths so, strictly speaking, should only be kept for three or four months (and never shared), then thrown away. Prolong the life of your mascara by making sure you screw the wand in properly – if air gets into the mascara it deteriorates faster. Don’t keep them for longer than six months or so – it’s easy to get eye and eyelid infections from contaminated cosmetics, which is why preservatives in these are so essential.

When choosing products, I prefer to look for those containing natural plant-based ingredients and plant oils. Check labels carefully and avoid anything with sodium lauryl/laureth sulphate (SLS), particularly for use on your face. Studies have shown that this chemical can irritate the skin, especially if you’re dry-skinned or prone to eczema.

Learning how to read a label can make us especially savvy when it comes to buying skincare devices: a product may proudly declare itself to be full of shea butter, but if on closer inspection you see it appearing towards the end of the list, then you can be fairly sure it’s more myth and marketing than beauty beneficial. Don’t be shy of preservatives. They are essential for keeping products safe, and much that has been written about them has been shown to be scaremongering and wrong.

Inside: Sugar – cut it down, cut it out

In the form of sweet foods and white refined carbs, sugar is the enemy of dieters; we all know it piles on the pounds. Research also suggests that sugar is at the root of much ill-health – and it is bad for your skin. If you have a high-sugar diet your skin will suffer like the rest of your body.

This is the result of a process known as glycation. When we have large amounts of sugar in the body, the sugar molecules attach themselves to protein molecules and form advanced glycation end products (AGEs). The more sugar in your body, the more AGEs will be formed. For our skin this is bad news. Skin proteins collagen and elastin are particularly susceptible to AGEs, so if your diet is high in sugar your skin is likely to wrinkle and age more quickly. You will also be more prone to inflammatory skin conditions, such as acne and rosacea.

When you look at your diet with a view to cutting down on sugar, it’s important to remember that it is not just cakes and the spoonfuls in your tea you need to watch for, it’s also refined carbohydrates such as white bread, white rice and pasta. Once digested these become sugar in the body. Fruit is high in sugar, but nature packages it with fibre and plenty of other good things, like vitamin C and beta-carotene, which are good for the skin.

Cutting out sugar in your tea and coffee and avoiding those biscuits, sweets and white bread might be hard, but at least it’s straightforward. What’s trickier is avoiding the hidden sugar in foods that you wouldn’t normally expect, such as tomato ketchup, canned soups, sauces and ready meals. Check labels for sugar content and avoid processed foods. Look at where sugar comes in the ingredients list – the higher up it is, the greater the quantity.

You can use artificial sweeteners, but some medics have concerns about their safety, and they don’t help to re-educate your taste buds to enjoy less-sweet foods. I prefer to stick mostly to fruit, dried fruit and small amounts of plant syrup and honey, with only the occasional spoonful of sugar. I also use dark chocolate as a sweet treat, and the great news is that small amounts are actually good for you! Stick with at least 70 per cent cocoa solids, which is rich in natural antioxidants and minerals. The high cocoa content has been shown to increase blood circulation to the upper layers of the skin, helping to give us a healthy glow. Don’t overdo it though – a couple of squares are enough …

SMART SWAPS

• Swap sugary breakfast cereal for porridge with a sprinkling of naturally sweet, crunchy sunflower seeds or flaked almonds.
• Swap white bread for wholemeal, or try my fabulously easy and delicious Rough and Tumble Bread (see here ).
• Swap biscuits for oatcakes spread with nut butter (see here ).
• Swap milk chocolate for a couple of squares of the dark stuff; look for at least 70 per cent cocoa solids on the label.

Outside: Start dry-skin body brushing

Body brushing is an easy, inexpensive treat for your skin and a great way to kick-start the day. You can do it yourself at home – all you need is a brush and a few moments of your time. It feels odd at first, but trust me on this one – once you get into the habit, you’ll love it, I promise.

Our skin is constantly eliminating waste products, and dry-skin brushing helps to remove these. It also boosts our circulation, exfoliates the skin naturally and smooths out little lumps and bumps – it’s really great for improving the appearance of cellulite. Brushing is best done in the morning before you step into the shower – if you stand in the light you’ll see scores of tiny skin cells hit the air. Choose a good natural bristle brush that’s firm enough to create friction but not so hard as to scratch or hurt your skin. The brush should have a good long handle to make it easier for you to reach all parts of your body, and it should always be used dry, on dry skin.

Start by brushing the soles of your feet, then work up your legs to your thighs and buttocks, using slow, upward strokes. Go gently over your stomach but don’t brush your breasts (the skin there is too fragile). Brush up your arms from your wrists to your shoulders – brushing is especially good for improving bumpy, pimply skin on flabby upper arms. Brush across your shoulders and down your back. Try to always brush towards your heart, as this helps the flow of lymph in the body. Avoid brushing any very sensitive areas or broken skin.

When you’re done, shower and moisturise as usual. You’ll soon notice the difference in your skin. Keep your brush just for you and wash it carefully every week, leaving it to air-dry naturally.

Inside: Cut caffeine and alcohol

Caffeine is a diuretic, so it dehydrates the body – not good news for the skin. It also increases the load on our liver, meaning that toxins (unwanted waste material the body naturally processes) are more likely to build up and manifest as skin problems.

I love my coffee, so I sometimes find my intake is creeping up and I have to cut back. I find total withdrawal just too sudden, as I get caffeine-withdrawal headaches, so I cut down on coffee and strong tea by one cup a day, until I’m down to one small mug a day at breakfast. From there, it’s easier to cut caffeine out altogether if you want to.

Start the day with a mug of hot water with a spritz of lemon instead. This gets the liver working and is a great way to reboot your metabolism after a night’s sleep. Lemon juice is detoxifying, cleansing and energising and packed with skin-friendly vitamin C. The rest of the day I tend to drink cleansing herb and spice teas, which are refreshing and do the skin lots of good. Fresh mint is an excellent internal cleanser and all you have to do is to steep a bunch of mint leaves in hot water for a few minutes, then strain; perfect after meals as a digestion aid and stomach soother. Nettle and fennel teas are also excellent and are available as dried loose teas and tea bags. Both are recommended frequently by herbalists as cleansing tonics, and are rich in antioxidants, vitamins and minerals.

Another drink I enjoy instead of coffee or tea is a spicy infusion of a few slices of fresh root ginger steeped in hot water (you can add a little honey, too). It’s antibacterial and an excellent system cleanser. Ginger is also known to be good for nausea or sickness – and hangovers!

That brings me to alcohol. Again, this can swiftly overload the liver and dehydrate the skin. Heavy drinkers may also find they get broken veins on the nose and cheeks. I must admit to liking a glass of wine, but it’s a good plan to cut your intake right down during this six-week plan to give your liver a break. You’ll see the difference in your skin. I find dark spirits and white wine are the worst offenders, so if you do want a little something, content yourself with the very occasional glass of good red wine – preferably organic – or a single shot of good-quality vodka with freshly squeezed fruit juice.

Make sure you’re drinking plenty of water (at least 1.6 litres), preferably filtered to remove the chlorine and nitrates, every day. It has tremendous benefits for your health and your skin.

Outside: Make your own face and body scrubs

Our skin is constantly renewing itself, as skin cells die off to be replaced by new ones. Every day we shed countless thousands of dead skin cells, while new plump skin cells are formed beneath the skin’s surface. Dead skin cells can clog the pores and lead to skin looking dull and tired, so a gentle scrub in addition to your regular cleansing routine can really help to instantly freshen the complexion. Young skins can take two or more gentle scrubs a week, but those with more mature skin are better off sticking to one.

And don’t forget the rest of you. A body scrub is really invigorating and improves the circulation, while leaving skin soft and smooth.

There are plenty of scrubs on the market, but you can make your own very quickly with ingredients from your fridge and store cupboard.