With summer approaching, it's that time of year again when we're all under pressure to hit the beach looking like Elle Macpherson.

The constant churn of new superfoods and perky Instagram health bloggers doesn't help either.

But what about those lucky (OK - annoying) people who never diet and stay slim - happily peeling off by the pool without a second thought? How do they get - and stay - slim?

Emily Muirhead, far left, 42, a GP from Ilkley, weighs 9 stone. Catharina Eden, second from left, 34, a bespoke wedding dress designer from London, weighs 9 stone. Eve Kalinik, third from left, 37, a nutritional therapist from London, weighs eight and a half stone. Gundula Hennig, third from right, 45, a personal trainer and manager at SP&Co, weighs eight stone eight lbs. Alex B, second from right, 58, a model with Grey Model Agency, lives in London and weighs eight stone eight lbs. Thane Prince, far right, 67, is a food writer from London and is a size 10

With summer approaching, it's that time of year again when we're all under pressure to hit the beach looking like Elle Macpherson. The constant churn of new superfoods and perky Instagram health bloggers doesn't help either

We meet six laid-back women who wouldn't dream of spending a small fortune on chia seeds or eating liquidised kale for breakfast.

Yet they are all lithe, healthy and bursting with energy - we'll have what they're having, please. Here's how they do it...

WRITE A FOOD DIARY

Emily Muirhead, 42, a GP from Ilkley, West Yorkshire, is a mother to three boys aged 10, 8 and 6. She is a size 10.

Emily Muirhead, 42, a GP from Ilkley, West Yorkshire, is a mother to three boys aged 10, 8 and 6. She is a size 10

Even though I've never dieted, my weight is always constant at 9 stone.

People say, 'Oh I can't help myself' when they overeat but you can. You just need to make a conscious decision - it's not rocket science.

I've got patients who can't believe they've got a body mass index of 40+. [Your BMI is a measure of whether you're a healthy weight for your height. Anything over 25 is considered overweight; over 40 means you're considered severely obese.]

People simply need to be honest with themselves. People often feel it isn't fair they're fat, that it isn't something they're doing wrong. But only a tiny proportion of people we test have a problem with their thyroid [which can cause weight gain].

I get people to keep a food diary - that's when you realise that your snack wasn't one biscuit, it was four. I could tell you exactly what I ate yesterday. There's a perception that you're either blessed or not with being slim, but it's not pre-determined, you make choices. I choose to get out of bed and go running at 6am.

But I never eat low-fat products - I'd rather have a small amount of something full-fat that tastes great than twice as much of something low-fat.

I also try to cook from scratch as much as I can, but I work a lot and have three young boys so that's not always possible - if we end up having frozen pizza one night, so be it. I eat crunchy oat cereal for breakfast that appears healthy but probably has way too much sugar in it.

I enjoy a chunk of Dairy Milk most days and always have Haagen-Dazs ice cream in the freezer. But I'm pragmatic about food - I don't attach any guilt to what I eat, I just monitor it. If my clothes start to feel tight I just eat less.

I OFFER BISCUITS TO MY BRIDES-TO-BE

Catharina Eden, 34, a bespoke wedding dress designer from London, is married with one nine-month-old son. She is a size 8.

Catharina Eden, 34, a bespoke wedding dress designer from London, is married with one nine-month-old son. She is a size 8

As far as I'm concerned, life is too short to begrudge yourself the odd biscuit. I always have a plate of them, or some cupcakes, when brides come in for a fitting and I'll say, 'You can have one, it's fine - it won't show when you put on the dress'. Yet 99 per cent of them won't because they're on a 'diet'.

I don't ban myself from eating anything - the minute you do that, you start craving it and end up indulging in a Snickers bar. To my mind, it's about moderation. I eat well but not to excess and so I've always weighed around 9 stone. My mum is the same and, like me, she won't hold back if there's carrot cake on the table.

I'm certainly no Gwyneth Paltrow - if I'm starving on the way home from work, I've been known to stop for a McDonald's burger and then come home and have dinner too! But I try to I eat three good meals a day, and I make them all myself - that way you know what you are eating and you have control over your diet.

I have oats, yoghurt, fruit and nuts for breakfast, an open sandwich on rye bread for lunch, with a stew or roast for dinner.

I graze a lot but I am careful to keep my snacks healthy.

Yes, I will eat biscuits at work, but I'll also take in hard-boiled eggs and walnuts to snack on, too.

I don't ban anything - I grew up with a fruit bowl on the table but also a bowl full of biscuits and chocolates.

It was always out on display, so it became normal rather than a rare treat and probably stopped me from counting calories.

my-eden.co.uk

KEEP LEFTOVERS OUT OF SIGHT

Thane Prince, 67, is a food writer from London married to a retired banker. She has two adult daughters and two grandchildren. She is a size 10.

Thane Prince, 67, is a food writer from London married to a retired banker. She has two adult daughters and two grandchildren. She is a size 10

Because of my height - I'm nearly 6ft - I can carry a little extra weight without it showing. But I only weigh 4lb more than I did in my twenties and I'm still the same clothes size.

I've written a dozen cookbooks and tasted everything in them, and I adore rich food - chips, millefeuille pastries, crisps with a G&T, plates of cheese with wine.

I take a credit/debit approach - for example, I'm going out for dinner tonight, so for lunch I'll have a bowl of homemade soup, without bread.

It's no great mystery why people are overweight - you simply have to take control of what you eat.

I think my age group are more mindful around food and how much we're eating - in my day, we'd never eat breakfast at our desk while working like people do now.

I think people make excuses for not eating well - even if you don't get home from work until 8pm, you can make a risotto with lots of vegetables when you get in. It takes 16 minutes, which is quicker than ordering a takeaway.

As a post-war baby, I was brought to eat everything on my plate, but I give myself smaller portions and move the leftovers out of sight, rather than putting the bowl on the table. I'm less likely to go back for seconds that way.

You can retrain your stomach and your palate - I've trained myself not to eat huge portions and to not have sugar in my coffee.

I'm careful not to eat too much fruit, as it can have a lot of calories, and I don't have things in the kitchen that are easy to snack on.

I also walk after dinner - my iPhone has a pedometer and I aim for 10,000 steps a day, but I'm not obsessive about it.

I live by the words of food writer Michael Pollan: eat food, not too much, mostly plants. That sums it up for me.

I WEIGH THE SAME AS I DID AT 18

Eve Kalinik, 37, a nutritional therapist from London, is single. She is a size 8.

Eve Kalinik, 37, a nutritional therapist from London, is single. She is a size 8

I get so annoyed by the current obsession with vilifying certain key food groups. It's not a good idea to cut out an entire food group because it can lead to nutritional imbalances.

Genuine intolerances do exist, but few people actually have them. I've got clients who jump from diet to diet, eliminating food groups and wondering why they never lose weight. If it sounds crazy, it probably is!

Bread has been demonised but I love sourdough - for lunch I might have scrambled eggs on sourdough toast, with proper full-fat butter.

I get so annoyed by the current obsession with vilifying certain key food groups. It's not a good idea to cut out an entire food group because it can lead to nutritional imbalances

Today I'll have salad for lunch and then chicken with butternut squash mash for dinner.

I have protein and good quality fats with every meal because they keep you satiated.

That means I very rarely snack - if you're eating three proper meals a day - and I never miss a meal - you don't need to. If I do think I'm hungry between meals, I drink herbal tea or water because often we mistake thirst for hunger.

I love food and I'll eat anything - I'm still the same weight (8 and a half stone) that I was when I was 18 so I must be doing something right.

Last night I had sea bream cooked in delicious pork fat at a restaurant. And if I'm out with a friend for coffee and I fancy a slice of cake, I'll have it. There's no guilt around food for me, it's there to be enjoyed. I'd rather have occasional treats like that than eat supposedly 'healthy' snack foods every day.

I also treat the weekend like any other day - if you tell yourself you're not going to drink alcohol or eat sweet things until the weekend, then you can end up bingeing.

Nutrition doesn't have to be complicated but people make a lot of excuses to not do things that'll benefit their health.

evekalinik.com

I LOVE A CROISSANT IN THE MORNING

Alex B, 58, a model with Grey Model Agency, lives in London and is a size 8-10.

Alex B, 58, a model with Grey Model Agency, lives in London and is a size 8-10

Eating well is common sense. Don't deny yourself everything - I love a mid-morning croissant or a slice of cake in the afternoon - but also don't overdo it. I'm very aware of portion size and will have one slice of cake rather than three, but I notice lots of people eating enormous sandwiches or piling their plates high and eating as if it's the last meal they'll ever have.

It's just not necessary. Obviously it's bad to be very thin, but it's also bad to be obese.

I'm Italian and I like pizza and pasta, but I'll have a small amount and savour it, rather than an enormous plate full.

I often have dinner at home on my own, but I ensure I make a proper meal, and I set the table and pour myself a glass of wine.

I like that ritual and it means I eat slowly, focusing on the food and how it tastes. I'll have chicken or fish, with lots of vegetables and maybe rice, drizzled with good olive oil.

Occasionally I have a small bowl of ice cream or a few squares of dark chocolate as dessert - it's so rich you can't have much. If you eat in the front of the TV, you gobble it down and lose track of how much you've eaten.

I didn't become a model until my mid-40s and with mature models there's less pressure on you regarding your weight, but I still like to maintain my 8 stone 8lb weight.

I'm naturally slim and have always been around this size, although I've put on a few pounds as I've got older.

I've met younger models who have been pressured to lose weight by bookers so they've left their agencies - girls seem more willing to stand up for themselves these days.

I tend not to eat during shoots, simply because it's not fair on the make-up artist who has to redo your lips after you've eaten.

So I sometimes miss lunch but I will then grab a sandwich, snack on almonds or have a bigger evening meal to compensate.

IF I GET HOME LATE, I MAKE A QUICK DHAL

Gundula Hennig, 45, a personal trainer and manager at SP&Co, lives in Richmond, Surrey and is a size 8.

Gundula Hennig, 45, a personal trainer and manager at SP&Co, lives in Richmond, Surrey and is a size 8

To be honest, I rarely get on the scales to check my weight (I'm around 8 stone 8lb) - I'm just not interested. All I care about is that my clothes fit.

After 45 years, you get to know yourself and your body. And as a personal trainer, I think about how what I put in my mouth fuels my body - it doesn't just disappear down your throat with no consequences.

That said, I don't punish myself: I love a big bowl of pasta at an Italian restaurant or if I'm ordering a burger, I'll always have fries, too.

I get hungry a lot so I always have snacks with me like nuts or fruit, and I drink a smoothie every morning. I eat porridge or eggs for breakfast, and I like spelt or rye bread as it's very filling, although sometimes I grab a croissant on the way to work.

If it's just occasionally that's OK, but if it starts happening three days in a row, I stop and think, why is this creeping towards being a habit?

I never diet though. I hate that word. I prefer to describe food as nourishment.

You have to listen to your body. I make sure I have good food in my cupboards and fridge so it's easier to make the right choices.

If I get home late and starving, I find sachets of ready-cooked Puy lentils very handy. I use them in a salad with goats' cheese, or I make a quick dhal.

I think we are all over-thinking food - there are so many fad diets and health bloggers around at the moment. How did we survive all this time until now without gluten-free this and that?

You just have to be happy in your skin and eat nourishing food that tastes great.