• Kayleigh Goodman

How to eat a sustainable diet for weight loss and planet

Updated: Oct 9

For many of us, the word "diet" is synonymous with weight loss. When we at Floop talk about sustainable diets, we mean choosing food that's better for the long term health of the planet. But when it comes to food choices, losing weight is a priority for many people.

A plant-based diet can reduce your carbon footprint. So I was curious... Can a diet that's sustainable for the environment also be sustainable for weight loss?

To find out, I spoke with Coral Sirett, a weight loss and nutrition coach. Coral is the founder of Zest Health and specialises in weight management through plant-based diets. She is also an expert in workplace wellbeing and the different experiences that shape our relationship with food.

Coral shared her personal journey with weight management and explained some of the drawbacks of popular diets, like keto and intermittent fasting. She also exposed some of the secrets we might discover about our eating habits using food diaries and shared her tips for building healthy food habits.

You'll also find Coral's healthy and sustainable breakfast recipes, and their carbon footprint, in the Floop app.

Plant-based nutritionist Callum Weir founder of Yumfu

Coral Sirett

Founder of Zest Health



✨ Get Coral's 5 Tips to Feel Body Confident

How did you become interested in weight management?

In my 20s and 30s, I didn't have the best relationship with food. My weight would fluctuate quite a lot. I drank quite a lot of alcohol at the time, would get frustrated with my weight and end up skipping meals. Then I'd end up eating more than if I hadn't skipped the meal in the first place... sit down and eat a whole packet of biscuits or a family pack of crisps in one go, so really not a healthy approach. I relied a lot on processed food and wasn't interested in healthy eating.

Then when I decided to become vegan, which was over 14 years ago, I wanted to do it right. I didn't want to be one of those people who became poorly or wasn't getting the proper nutrition. So I decided to start educating myself and reading about nutrition. I realised I hadn't been eating that well, so that's when I started [eating more] whole foods.

From that, I decided to study nutrition and weight management formally so I did a course to get an advanced diploma because I wanted a qualification that was recognised in the UK. I also decided to study plant-based nutrition with eCornell in the U.S., in conjunction with the Center for Nutrition Studies by T. Colin Campbell, who some people may know from The China Study.

Most people's weight fluctuates to some extent, particularly for women. The weight that I struggled to shift for years started to come off, and even before that time... when I've been intensive training for marathons... I'd really struggled with my weight still. This was just a much more effortless way to do it. I got down to a healthy weight, and I've stayed there ever since without trying.

I started to see more reports about obesity and how being really overweight is causing a lot of issues for people on a very personal level and costing the NHS huge amounts of money to treat conditions associated with that. So I decided I wanted to be part of the solution.

You say your weight started shifting when you began eating more plant-based whole foods. How does a plant-based diet compare to other popular diets... like keto, intermittent fasting, paleo, etc?

The word diet has got different meanings in different contexts. I know for many people when they think about the word diet, they'll have connotations about it being something that's difficult, or about deprivation, or something that's very restrictive.

If I talk about a plant-based diet, I'm talking about a way of eating. It's a way of eating... not something that you "go on". I think the aim of many of those other diets is they can be a diet that somebody goes on, and then they come off it again and start eating normally, whatever that means for them.

The focus tends to be on weight loss and sometimes it can be rapid weight loss. People are often looking for a quick fix, even if deep down they know those quick fixes don't work because they might have done them before. It's just a thing in human nature, you know? We want results; we want things done quickly.

Some of those [diets] you've mentioned will offer results in the short term, but if you want something healthy, as well, and has been shown to reverse conditions such as Type 2 diabetes or even heart disease and certain cancers, then you can't really beat a whole food plant-based diet.

Things like intermittent fasting have been shown to have some health benefits, but I do think there's another side to them that is just worth being aware of. Many people find them very difficult, but some people do quite well eating one or two meals a day, so you're eating the same calories but in fewer meals. If you're going for something like the 5:2, so many people struggle with the two days because they have to be very strict with the calories. It's normally 500 calories, I mean that's incredibly low. The attitude is not about the quality of the food consumed, it's just so calorie centric. A calorie is not just a calorie.

There has been quite a lot of research around the best way to lose weight and maintain it. One of those is what's referred to as calorie loading. So, you eat more of your calories earlier in the day.

There's this old phrase about breakfasting like a king, lunch like a prince, supper like a pauper. It makes sense, you know? It works really well for a lot of people. If you've only got eight hours to cram it in, that can be quite difficult but some people do quite well eating same one or two meals a day so you're eating the same calories but in fewer meals and that can work for some people but

When I'm working with clients, I find the best thing is to try to support them with habits and routines similar to what they're used to. You'll not have to make massive changes. We're just adjusting the type of food they're eating, which makes it much easier to fit in around family and other commitments.

You can generally eat a lot more whole foods as they're not so calorie-dense. So if you like your food, it's great because you can have a massive bowl of food and you're still gonna lose weight if weight loss is what you're aiming to do. With plant-based, you will have guidelines about eating as much whole food as possible, but you don't have these strict rules to measure things that can sometimes trigger people with a poor relationship with food or disordered eating. With plant-based, you are focusing on nutrition as well as weight loss. [My view on diets like] intermittent fasting is that they're not always great for long-term health, even though they might get people the results they want. Long-term, a whole food plant-based diet is the best for those health outcomes as well as weight loss.

There's growing research that eating a mostly plant-based diet is more sustainable for the climate and for the environment overall. How sustainable would you say it is for your health and for weight loss?

I would say very, because it's not about deprivation and you don't have to get bogged down with calorie counting. It's very sustainable in terms of being able to follow it long term and it's up to you, as obviously this is a very individual thing, as to how much you adopt a plant-based diet. Whether it's 100% or most of the time or some of the time. I think that will depend on your reasons for wanting to make the change.

In my experience, quite a lot of people have a difficult relationship with food. Emotional eating is an issue for the majority of people that have concerns over their weight.

Some of that can be they've developed an addiction to certain types of food - particularly sugary food - and I feel that not enough is said about food addiction. I saw a sign the other day for some nicotine patches and there was a warning about how addictive nicotine is. I think most people would know that, but people don't necessarily always think about how addictive sugar is.

The addiction side of things isn't really spoken about. But it would probably be best for some people not to have anything sugary at all, and stick to whole food as much as possible to give time for taste buds to adjust.

Other factors need to be taken into account, such as stress management. Certain times can be incredibly difficult. Most of us have got stuff going on on a personal level, but we could be taking on board what's going on in the world.

In terms of your question about sustainability: some of the longest-living and healthiest people in the world, in areas known as blue zones, will be eating a predominantly plant-based diet.

One of your first activities with a new client is to ask them to keep a food diary. What do people tend to notice when they keep a food diary for a few days?

For a few people, it's been a real eye-opener. We can be quite dishonest with ourselves. For many people their decision to eat is not always driven by hunger. It can often be in response to something stressful or something upsetting, which is why I don't just ask people to record what they eat. I ask them to record how hungry they are on a scale and their mood so we can see what we might need to focus on if they are eating in response to certain emotions. It's really common for that to be the case, so for anyone who feels like that please don't feel you're unusual.

It's common for people to realise they're not eating as well as they'd like to think, so even if you're not being dishonest, you might just think that you are eating better than you are.

They are often surprised by how much packaged food is on [the diary]. We might pick a couple of those things, and I'll highlight how many teaspoons of sugar is in it.

I offer that service as well to people who aren't just coaching clients, so if somebody just wanted to know where they were at and they wanted some recommendations as to some changes it's a really good way of giving them a snapshot of their diet now and what they could do to make changes they could implement.

What is the biggest barrier to creating new food habits? How can someone overcome these?

There can be a few depending on the person. It doesn't always work just telling somebody what to eat. Many people that come to me say they know what they need to do; they're just not doing it. So support and accountability are really important.

People often decide to do too much, as well. If you want to make not just new food habits but new healthier habits, they might decide they're going to start running four times a week, eating healthily, and making a smoothie every day. But they haven't really planned it out, and they've been quite unrealistic. I discourage people from doing that because if you plan to do all these things and then don't do them, it can demoralise and demotivate you.

The important thing is not to get overwhelmed and to tackle one issue at a time. Be realistic. If you feel you haven't got the time now, how are you going to get the time? We've all got the same number of hours in the day but are we spending them in the best way for us and for everything going on in our lives.

Some people can find it quite difficult if they don't have positive support from friends and family. If you can get support, it can make a real difference. I would advise people to explain what you're doing and to make it about how eating a certain way makes you feel better, to make sure people don't feel they're being judged or criticised for not doing the same. I experienced that quite a lot when I decided not to drink anymore. It's important that people don't feel you're criticising their decisions because it isn't about them. It's what you want to do for yourself, and you don't want people feeling guilty and awkward about it.

There can be this perception that it's complicated and time-consuming. So I focus on recipes made with familiar ingredients that people can get from a supermarket, and they don't have to be searching online and traipsing specialist shops. Recipes that can be made in under half an hour or, if they take longer, make a big batch of it to get six meals out of it. You've only cooked fresh once and saved loads of time.

I provide meal plans when I'm working with clients, but I encourage them and show them how to do their own meal plans. I think people can feel that's a bit of a drag to sit there planning out what they're going to eat. But it is a plan and it's not a strict thing. If on Monday night, you don't fancy a chilli, you just swap your food for something else. A plan can save a lot of time, you're not going to the shop so often, you're not wandering up and down deciding what to eat if you put it in the right order of the shop. It also means you'll probably waste less food which is a thing that I'm very passionate about. And you cut calories if needed and stick to healthier foods.

If you've other family members who don't want to eat the same way, then I will go through their family favourites and we'll talk about veganising those. People can often be quite surprised, actually. They think their family won't enjoy things but I've had feedback from some of the meat eating members of the family on how much they've loved the burgers and the chilli. If you can get your family onboard that's great, or just swap out certain ingredients. Swap the meat for beans or lentils. Keeping things quite familiar, as well, really helps.

Sometimes we can perceive things will be more difficult than they are. Another perceived barrier can be the cost. I was reading an article the other day about how people have been affected by the fuel prices in the UK. Somebody said they'd stopped buying meat and they were just consuming carbs which they said wasn't good for them. I thought I'd love to get in touch with this person and say you just need to swap with that meat for pulses. There can be this perception that healthy eating is expensive. I worked out that the burgers on my website cost about 10p and you can make them in 15 minutes. Things like bags of rice and either dried beans and chickpeas and lentils or tinned - they're not expensive. They can be the basis for many meals once you get to grips and get more familiar with different herbs and spices and cooking techniques.

I would say just do one thing at a time. If you want to aim for one plant-based meal a week then start there and see how you get on. I think it's important to have compassion and tolerance for other people's journeys, and ways of getting to the place that they feel is right for them.

What other questions do you have about plant-based diet? Let us know in the comments below 👇