Will you lose weight on a plant-based diet?

Over the last few years it’s become the food trend to follow, but is a plant-based diet an effective weight-loss plan?

For many people, ‘plant-based’ is not so much a diet as a lifestyle choice driven by environmental, ethical and health concerns. However, with celebrities including Beyonce using it for weight loss, and Kim Kardashian-West reportedly saying it was partly responsible for her small waistline, people are tempted to follow it for the same reason. But is it effective? We asked the experts…

What does plant-based mean?

Does ‘plant-based’ mean vegan, vegetarian, or something else? Well, it could be any one of these things. “Many styles of eating are mainly plant-based, but can also include meat or fish – for instance a Mediterranean-style diet, or the balance of foods in the Eatwell Guide, the Government’s healthy eating model”, says nutrition scientist Dr Simon Steenson of the British Nutrition Foundation.

“I’d say someone following a plant-based diet would be eating [at least] 85–90 percent whole plant foods”, says Dr Shireen Kassam, consultant haematologist who heads up the Plant-based Nutrition course at the University of Winchester.

So what does a healthy plant-based diet look like? “It’s about eating equal proportions, like a plate cut into quarters, of fruits, vegetables, wholegrains (as opposed to refined grains) and plant protein predominantly from legumes, beans and pulses, and then most days a handful of nuts and seeds”, continues Kassam.

It can be effective for weight loss

“Scientific studies that have looked at non-vegan populations over 20-30 years show those eating the most plant foods tend to put on less weight over time than those eating the most meat, dairy and eggs”, says Dr Kassam. “There have been research groups, including at Harvard and the Epic study in Europe, which have been following people for 20-30 years. When you add to these the work of Dan Buettner, which looks at populations where people are likely to live to 100, [there is evidence] people who are eating about 85 percent plant-based foods live longer and are healthier, with less disease”, she continues.

‘Plant Power Doctor’ Dr Gemma Newman, a senior partner at a doctors’ practice, says “If you are going for a plant-based lifestyle, try to make it whole-food based”. She recommends experimenting with foods and recipes so you don’t feel your diet is restricted, and filling up on starchy fruit and veg. While she advises eating legumes such as chickpeas, lentils, split peas, black beans and butter beans, as “they’re full of protein and fibre and are really going to improve the health of your gut”, she warns if you haven’t eaten many before you should start slowly and gradually build up your gut tolerance to avoid bloating.

When plant-based won’t result in weight loss

Like-for-like junk food replacements aren’t necessarily better for you just because they’re vegan. Switching from a sausage roll to vegetarian sausage roll isn’t necessarily a healthier choice, and nor does it mean you’ll lose weight.

“Some products or meals may contain a lot of saturated fat or salt, which we should aim to limit”, says Dr Steenson. You can compare the amounts of these nutrients by looking at the label or using the traffic light symbols on many products.

Dr Newman adds: “People think, ‘Oh, plant-based diet, I’m going to automatically lose weight’, and sometimes they do it solely for that purpose, which in some cases can be harmful. Weight is a hugely complex issue. It’s not just a simple equation of food in and energy out, it’s determined by a whole host of things: our food environment and what shops we have access to, how we’ve been brought up, even things like if we do shift work or if we’re stressed.

“A common trap is that rather than having dairy ice cream you might have vegan ice cream, which is not a health food. But having said that, there are healthier choices. Take burgers for example – a beetroot burger or bean burger is going to be healthier than a processed soy burger. But they’re probably all slightly better choices than a standard beef burger.”

Plant-based food labelling, especially when combined with ‘low-fat’ or ‘high-fibre’, might confuse shoppers, according to Dr Kassam. She warns it can “make people think they’re eating something healthy, but really it’s all been turned upside down. Anything with a label should be viewed cautiously. If you are eating foods with labels, look for those containing fibre or fewer ingredients and be mindful of the salt, fat or sugar content.”

Should you count calories?

“You don’t need to worry so much about portion control or calorie counting if you’re centring your diet around the four food groups [fruit, vegetables, whole grains and legumes]”, says Dr Kassam, because “most plant foods have a much lower calorie density than animal derived foods”. Plant foods are also generally nutrient-rich.

Dr Newman warns against restricting your calorie intake while following a whole-food, plant-based diet. She advises if you need to lose weight, “for most people, eating when you’re hungry and stopping when you’re full is more than enough”.

Supplement your plant-based diet

All the experts agree that if you’re following a 100 percent plant-based diet you’re going to need supplements and/or fortified foods to ensure you’re not missing out on vital nutrients.

“If you are trying a vegetarian or vegan diet, it is important to think about which foods you can eat to provide important vitamins and minerals, such as vitamin B12, iron, calcium and iodine”, says Dr Steenson. Experts also mentioned the importance of ensuring you are consuming enough omega-3. “Vitamin B12 in particular isn’t generally found naturally in plant foods, so it’s important to have fortified foods or supplements if following a vegan diet. Some plant-based dairy alternatives, such as oat, soy and almond drinks, are now fortified with calcium and other nutrients, but check the label to see if it contains added vitamins or minerals”, she continues.

But don’t get too caught-up in weight loss

“The key is to really focus on healthy choices over losing weight. Yes, a whole-food, plant-based diet will be helpful, but also think ‘are there other things which could help improve my health?’”, Dr Newman says. “Even if you’re overweight, if you’re focusing on eating five or more servings of fruits and vegetables [a day], taking regular exercise, limiting alcohol and not smoking cigarettes, you’re still going to reduce your risk of dying younger.”