The 16-day diet that will help you lose half a stone

Petronella Ravenshear remembers being quite cynical when clients told her that, despite trying, they couldn’t lose weight. 

She admits to thinking they were making it up. That they must really be lying on the sofa and scoffing chocolate. That was until she hit menopause and she says: “Thank God it happened to me. I was eating less and less, doing more exercise and I was getting fatter and fatter.”

The nutritionist had studied at the Institute for Optimum Nutrition, but it was studying metabolic balance with the late Dr Wolf Funfack in 2008 that completely changed her opinion of what the body needs.

She believes restricting calories and cortisol-raising intensive exercises actually lowers metabolic rate, particularly as we age and body composition changes.

And so when her own middle-age spread began – her weight increasing from 54kg to 63kg – she devised a programme for herself to get back to her original weight. 

Now in her 60s, Ravenshear says: “I was very grateful for that lesson from my body.”

So too were her clients. 

The effectiveness of her programme – an average weight loss of between five to 14 pounds in 16 days – spread by word of mouth. Friends asked suddenly much slimmer friends how they’d done it. The answer: the Human Being Diet, aka HBD. 

With her private practice on a waitlist, even when she put her prices up, people kept coming. 

“It seemed really unfair,” she says. “People shouldn’t have to be wealthy in order to understand how to change their health and how to get more joy out of life.” As a result she wrote her book, first published in 2018, The Human Being Diet, giving people at home the tools to make the transformation for themselves. 

What is HBD?

The aim of the HBD is to say goodbye to ‘the sugar monster’, stabilise insulin release and lower inflammation by eating real, nutritionally dense food. There are no meal replacement bars or shakes. Everything you eat can be bought at your local supermarket. 

“Weight Watchers and Slimming World are not teaching people about eating real food. This is about connecting with food that our DNA recognises as sustenance,” says Ravenshear.

While similar to a Mediterranean diet, HBD isn’t big on pulses and grains. Instead it focuses on vegetables and high-quality protein such as fish and eggs. 

“Fats and proteins are the only two essential food groups. Carbs are an option,” states Ravenshear. 

When we think of carbohydrates we tend to think of grains and sugary things, but fruit and vegetables are also carbs. So although she advises eating them at every meal, portion sizes are still measured. “Vegetables may be very low calorie but if we load up too much we don’t burn fat, because all those vegetables are ultimately broken down to sugar.”

When we eat something sugary, the body thinks that is a dangerous thing and releases insulin. The insulin does its job to take the sugar out of circulation and into the cells where it can be burnt for energy. “Very often it does its job too well. So the circulating blood sugar level goes lower than it was before. At which point it is almost impossible to stop looking for a sugary snack,” says Ravenshear. 

Vegetables, however, are a good course of fibre, vitamins and minerals. “So even though they are not deemed essential, they are in fact essential to good health.” 

However Ravenshear is not a fan of whole grains. “People think they’re doing the right thing by eating them but the wheat protein, part of the gluten molecule, is small enough  to cross the blood brain barrier. There it attaches to the opiate receptors, which is why wheat becomes addictive.”

Wheat and grains aren’t recommended at the start of the diet. Wheat is associated with a leaky gut, which allows partially digested food to pass into the bloodstream, “which activates the immune system and saps our energy”. It is also a common allergen.

Quinoa meanwhile, says Ravenshear, is simply a carbohydrate with good PR: “It contains five times more carbohydrate than protein.”

It’s worth noting that pulses are carbs containing some protein rather than protein foods. 

The #HBD community

There’s no doubt that the support and a sense of belonging add to the diet’s success. Today #HBD has a thriving community on Instagram. The hashtag is a way for other “HBD-ers” to find each other and importantly, encourage each other. “It’s hugely honouring. It is a really lovely safe space for people,” says Ravenshear.

The community aspect is especially important as the first 16-days of HBD are difficult. Being in touch with others on the journey gives people accountability and responsibility. 

“It might be really hard one day and you go on Instagram and pick up inspiration. It helps you to connect to your ‘whys’,” says Ravenshear. Why did you start HBD in the first place? What did you want to change? What was your inspiration?”

It’s a forum for sharing successes, particularly the non-scale victories. Because it is not all about weight loss. 

One HBD-er Clare overcame chronic fatigue syndrome (also known as ME) fibromyalgia and her doctors’ prognosis of life in a wheelchair. “She’s now, thanks to HBD, a dedicated runner and gym bunny,” says Ravenshear.

Followers of HBD have also seen improvements in health concerns such as IBS and hormonal issues from PCOS to menopause, as well as skin disorders, depression and fatigue.

She has found fans within the medical community as well. Dr Mike Seddon, a consultant cardiologist, has embraced the HBD philosophy together with his wife and many of his colleagues. “The human being diet is founded on robust and very accessible science combined with a lifetime of clinical experience,” he says.

The 16-day detox 

Getting started on HBD is not for the faint-hearted. The first 16 days, known as The Reset, it should be done only once, maximum twice, a year. It is not recommended for those under 18 or those who are pregnant or breastfeeding.

A radical detox that aims to strip you down and rebuild a new way of life, while HBD isn’t a calorie counting diet, the first 16 days are low-calorie; around 700-900 calories a day: “Which has a positive effect on our microbes, which is in turn good for us,” says Ravenshear. 

While long periods of calorie restriction can cause metabolic rate to lower, scientific studies have shown that in the short term there are associated anti-ageing effects, as well as benefits to blood pressure and longevity. 

However, the first 16 days are tough. “Usually people have read the book and they’re really clear about their whys,” says Ravenshear. If your why is to lose weight then commitment in the first 16 days is crucial. This is when most weight is lost on HBD. 

Phase One: Two days

Two days of eating vegetables. This is to feed the gut, where your detox begins, and also begin to isolate potential allergens. 

That means no oil (just to keep calories low), no grains, no dairy, no protein, no pulses, no alcohol. Avocados and tomatoes, while fruits, are allowed. Potatoes are not. 

If you have any chronic pain or an autoimmune condition then other nightshade vegetables, such as peppers, tomato and aubergine are also off the menu. 

Organic apple cider vinegar (ACV) as well as salt and pepper, fresh and fried herbs are your flavour friends here. 

“People often batch cook soups for this phase,” says Ravenshear. 

Going cold turkey off sugar might result in headaches: “It’s not uncommon for people to have flu-like symptoms. You’re getting rid of all the rubbish and just giving someone fresh vegetables. It is quite hardcore.

Phase Two: 14 days

Now the food weighing starts. Again, there is no oil, alcohol, sugar, wheat or grains. But pulses, fruit, nuts or seeds and other protein foods are reintroduced. 

Breakfast is 100g of a protein-rich food with 100g of vegetables. You can choose either chicken, turkey breast (no skin), fresh salmon, or two eggs. Or 35g of sunflower and pumpkin seeds with one grated apple. 

If you weigh less than 65kg then you eat 120g of protein and 120g of vegetables for lunch and dinner. If you weigh between 65-80kg you eat 130g and if you are more than 80kg then this is 140g.  

The aim is three meals a day with five hour fasts between meals. This is to help lower insulin and give the digestive system time to clean up undigested food and fibres. You can only drink plain water in between; anything else has the potential to mess with our blood sugar.

Breakfast is important, Ravenshear says, because it resets our circadian rhythm and also leptin sensitivity. “Leptin is one of the hormones that can go AWOL in midlife. If we don’t have enough leptin, or if our brain isn’t sensitive to leptin, then we are always hungry. So eating breakfast first thing in the morning resists that sensitivity.”

It’s best to avoid dairy (because it’s a common allergen) until phase three. And milk is definitely not allowed: “We’re looking for high protein foods, and milk, although a proper food is mainly water compared to yogurt or cheese. 

If you are going to eat dairy, the HBD advice is to eat full fat dairy (including yogurt and cheese) because studies have shown that full fat can keep you fuller for longer. And avoid processed cheeses such as cream cheese. 

Ravenshear stipulates one type of protein per meal. “If we’re mixing different proteins we may be absorbing less pure amino acids than if we were having one type of protein.”

Eggs are the perfect protein because they’ve got all the amino acids and in the right ratios for us to make our internal proteins.

Protein not only helps with satiety but we are made of the protein that we eat.” It builds our muscle and our skin and hormones and immune cells,” says Ravenshear. “Plant-based folk often ask me if they can follow the programme and I say unless you eat tofu or tempeh, the programme won’t work.”

After each meal you’re allowed a piece of fruit, but one of those in the day has to be an apple: “The benefits outweigh the negatives of fructose,” says Ravenshear.

Exercise

Strenuous exercise is forbidden. Not only are you not eating enough to fuel workouts, the aim is to help your parasympathetic nervous system, which helps the body relax.

“Strenuous exercise is a stressor which can trigger cortisol. There’s a big link between excessive amounts of cortisol in midlife and weight gain, which is why midlife ladies find it difficult to lose weight.”

Yoga, Pilates or walking are all fine. 

Post-detox

As Day 17 dawns the main effect of the detox will be weight loss. 

More importantly perhaps, blood sugar levels will have stabilised and as a result you may feel less hungry than you were pre-HBD (despite eating smaller portions) and suffer fewer cravings. “People also enjoy better energy and a brighter mood,” says Ravenshear.

“Because inflammation is already reduced in the first two weeks they also suffer fewer aches and pains – sometimes they’ve disappeared altogether.”

On an emotional level HBD-ers are more aware of how they are actually feeling. 

“We reconnect with a feeling of hunger. We often eat as displacement activity, because we are bored or comfort eating and we learn to recognise that,” says Ravenshear.

There’s also a recognition of one’s resilience. “It’s pretty darn tough the first 16 days and you may never have thought  you’d have the willpower to do it.”

Phase Three: 10 weeks

In its entirety HBD is a three-month programme of four phases. 

Phase three is designed to last 10 weeks. This is where extra virgin olive oil is added. “It doesn’t sound very exciting but it really is after 16 days of no oil. People can cook with it or add it to salads.”

The best part of stage three for HBD-ers is that you can have a treat meal once a week. 

“Sometimes people feel ill after their treat meal and then that gives them a clue about which things are best avoided. It could be gluten, sugar, dairy, or alcohol.”

HBD-ers stay in phase three until they’re happy with their weight loss, or for a maximum of 10 weeks. 

The forever phase

After 10 weeks new healthy habits should have embedded themselves.  

By this point HBD-ers have learnt what foods suit them and which foods don’t. “And that’s where they stay,” says Ravenshear. “That is their new lifestyle.”

It is what sets the HBD apart from other diets. “It’s adopting a whole new lifestyle with no end.”

Meal plan and recipes

For phase one, you can include fresh/dried herbs for flavour and fresh veg or chicken stock for your soup base. An apple a day for phase two is a must, extra fruit is optional. As for phase one, use fresh/dried herbs for flavour and fresh veg or chicken stock for your soup base or for stir-fries. You can have unsweetened black tea and coffee with meals but between meals it’s just water.

Recipes

From the HBD Cookbook by Petronella Ravenshear

Spaghetti squash with kale and baby plum tomatoes

• Serves: 2
• Prep time: 20 minutes
• Cook time: 30 minutes

Ingredients

• 1 medium spaghetti squash, split lengthways and deseeded 
• Pinch of ground cinnamon 
• 100g baby plum tomatoes, halved 
• 1 red onion, thinly sliced 
• 2 garlic cloves, crushed 
• Pinch of crushed dried chilli or red pepper flakes 
• 75ml good-quality vegetable stock 
• 200g kale, trimmed and coarsely shredded 
• 1-3 tsp apple cider vinegar 
• Small handful of flat-leaf parsley, chopped

To serve 

• Sea salt and freshly ground black pepper

Method

1. Preheat the oven to 200C/180C fan/gas mark 6 Line 2 baking trays with baking parchment. 
2. Prick the skin of the squash a few times with a fork. Dust the inside of each squash half with cinnamon and season lightly with salt and pepper, then place them on one of the lined baking trays, cut-side down. Place the tomatoes, cut-side up, on the other lined baking tray and season with salt and pepper. 
3. Bake the squash and tomatoes in the oven for 25–30 minutes, or until the strands of squash are just tender (but not mushy) and the tomatoes are starting to char. Remove from the oven and when the squash is cool enough to handle, scrape out the strands with a fork. 
4. Meanwhile, put the onion, garlic, chilli or red pepper flakes and 2 tablespoons of the vegetable stock in a frying pan over a medium heat and cook, stirring occasionally, for 6–8 minutes. Stir in the kale with the remaining stock and simmer gently for 3–4 minutes, or until the kale wilts and the liquid has been absorbed. If it’s dry, moisten with another spoonful of stock.
5. Stir in the apple cider vinegar, and fold in the squash strands and tomatoes. Toss together gently. 
6. Divide the mixture between 2 serving plates and sprinkle with chopped parsley.

Zingy aubergine and tomato curry 

• Serves: 2
• Prep time: 15 minutes
• Cook time: 30-35 minutes

Ingredients

• 2 onions, chopped 
• 3 garlic cloves, crushed 
• 2.5cm piece of fresh ginger, peeled and diced 
• 300ml good-quality vegetable stock 
• 2 tsp ground turmeric 
• 1 tsp ground cinnamon 
• 1 tsp ground coriander 
• ½ tsp ground cumin 
• 3 vine tomatoes, quartered or cut into chunks 
• 1 medium aubergine, trimmed and cubed 
• 250g fresh spinach leaves, washed, trimmed and shredded 
• Handful of coriander, chopped 
• Sea salt and freshly ground black pepper

Method

1. Put the onions, garlic, ginger and stock into a large saucepan over a high heat. Cover the pan, bring the stock to the boil and then boil for 10 minutes. Reduce the heat to low, remove the lid and cook gently for 20 minutes, or until the onions are tender, golden and syrupy.  
2. Stir in the ground spices and cook for 3–4 minutes. Add the tomatoes and aubergine, and cook gently, stirring occasionally, for 6–8 minutes, or until just tender. Keep checking the pan to ensure you don’t overcook the aubergine. 
3. About 3 minutes before the end of the cooking time, stir in the spinach and cook until it wilts and turns a lovely shade of green. Season with salt and pepper to taste and stir in most of the coriander. 
4. Divide the curry between 2 serving plates and sprinkle the remaining coriander over the top.

Green shakshuka

• Serves: 2
• Prep time: 10 minutes
• Cook time: 15 minutes

Ingredients

• 60ml good-quality vegetable stock 
• 10g spring onion, thinly sliced 
• 1 garlic clove, crushed 
• 1 red chilli*, diced 
• 75g thin asparagus spears, trimmed and halved 
• 75g broccoli florets 
• 40g spinach, trimmed and chopped 
• Small handful of flat-leaf parsley or dill 
• 4 organic eggs 
• Sea salt and freshly ground black pepper

Aegean fish stew

• Serves: 2
• Prep time: 15 minutes
• Cook time: 25-30 minutes

Ingredients

• 350ml good-quality fish or vegetable stock 
• 50g onion, diced 
• 160g butternut squash, peeled and diced 
• 1 garlic clove, crushed 
• 50g courgette, sliced 
• Pinch of crushed chilli flakes* (optional) 
• Pinch of saffron threads 
• 1 bay leaf 
• 260g mixed firm fish fillets, eg cod, sea bream, sea bass, red mullet, salmon, cut into chunks 
• Handful of flat-leaf parsley, chopped 
• Sea salt and freshly ground black pepper

Method

1. Put 3 tablespoons of the stock into a large saucepan over a low to medium heat. Add the onion, butternut squash and garlic and cook for 8–10 minutes, stirring occasionally, until they have softened. If they start to become dry, add a little more stock. Take care that they do not brown. 
2. Stir in the courgette, chilli flakes (if using) and saffron. Cook for 1 minute and then add the remaining stock and bay leaf. 
3. Bring to the boil, then reduce the heat immediately to barely a simmer and cover the pan. Cook gently for 10 minutes, or until the vegetables are tender. Add the fish and simmer for a further 5 minutes, or until it is just cooked and opaque. Check the seasoning, adding salt and pepper to taste, and stir in the parsley. 
4. Ladle into 2 shallow serving bowls, dividing the fish equally between them. Serve immediately.

Stir-fried ginger chicken and greens

• Serves: 2
• Prep time: 15 minutes
• Marinate: 10 minutes
• Cook time: 10-12 minutes

Ingredients

• 260g chicken breast fillets, skinned and cut into small cubes 
• 2.5cm piece of fresh ginger, peeled and diced or shredded 
• 2 garlic cloves, crushed 
• 1 lemongrass stalk, peeled and thinly sliced 
• 1 tbsp lemon juice 
• 4–5 tbsp good-quality vegetable stock 
• 50g leeks, washed, trimmed and shredded 85g asparagus, trimmed and cut into short lengths 
• 25g celery, cut into short lengths 
• 100g spring greens or spinach leaves, washed and shredded 
• Sea salt and freshly ground black pepper

Method

1. Put the chicken cubes in a bowl with the ginger, garlic, lemongrass and lemon juice. Stir gently to coat the chicken pieces, then set aside in a cool place for 10 minutes to marinate. 
2. Put 2 tablespoons of the vegetable stock into a non-stick wok or frying pan and set over a medium to high heat. Add the chicken and ‘stir-fry’ for 4–5 minutes until cooked through and golden brown all over. 
3. Add the leeks, asparagus, celery and greens and ‘stir-fry’ for 4–5 minutes, adding more stock as necessary to keep the vegetables moist, until they are cooked and the asparagus and celery are just tender but still have some bite.
4. Season to taste with salt and pepper and transfer to 2 serving bowls. Serve immediately.