Going on a crash diet and losing 10 pounds in a week, or even 20 pounds in a month, is an attractive proposition for anyone who wants to slim down for the summer.
Yet if you pick the wrong quick-fix solution, you could end up gaining weight in the long run or missing out on key nutrients while you hyperfocus on one aspect of your wellbeing.
As marketing teams highlight the miraculous powers of numerous different weight-loss plans – from the vegan diet to the Mediterranean diet, from intermittent fasting to the Dash diet – selecting the right one can feel like a minefield.
Dr Annabel Fountain, the medical director at Fountain Health, encourages people to pick a nutrition plan that works for them in the long run.
She said: “Saying ‘I’m going on a diet’ indicates that you’re changing something and that you are restricting. Whereas if we all just pick what works for us – because it’s healthy, our bodies like it and we can sustain it because we like it – then it doesn’t really matter which of the nutrition plans you pick.
“The best nutrition plan is the one you can maintain. That means you have a plan and it’s not just random, it’s sustainable.”
Sarah Wight, a nutritionist at Ocean Rock Wellness, warned about the unsustainability of restrictive diets, which claim to deliver results in a few weeks.
“After a person completes a diet they will often return to their old habits of eating,” Ms Wight said.
“I don’t think ‘going on a diet’ is ever a good thing unless a client or person absolutely needs to lose weight for a medical reason in a short period of time.
“If women have been on numerous diets throughout their life, I often find that later, when they’re in their 40s or 50s, they experience resistance weight loss. That’s because their bodies have gone through stress and our bodies remember that when we reduce nutrients we go into a starvation mode.”
Dr Fountain further explained: “With very severe calorie restriction, people will lose weight but their metabolism now thinks they are starving. When they go back to eating the way they were eating before, they are quite often going to gain more weight than they lost.
“There are also some extreme ways of eating where you could have some nutritional deficiencies. Most people who decide to be vegan, for example, will look on the internet and realise they have to take supplements.”
Marketing around dieting also causes people to hyperfocus.
Ms Wight said: “Diets don’t teach us nutritional literacy and they don’t educate us. If a person goes on a diet, the only thing they learn is what to eat or not eat. They don’t learn about why, or the overall picture of their health.
“When we learn about diets, it’s often through marketing campaigns on websites and social media that want us to buy their product. We are not learning about them in an informed environment.”
One of the most popular diets today is the vegan diet, in which people only eat only plants and foods made from plants, which could lead to a deficiency in calcium and vitamin D.
Dr Fountain advised: “There is no B12 in plants. B12 is essential for your brain health and your nerves. Vitamin D is extremely important for your health, and that’s mostly in oily fish, eggs and dairy products.
“But a lot of processed foods contain vitamins. For example, bread might have B12 added to it and vitamin D is added to some plant milks.”
Another diet is intermittent fasting, in which people restrict eating to a six- or eight-hour period each day, or only eat one meal a day for two days a week. This causes the body to exhaust its sugar stores and start burning fat.
Ms Wight said this can be very effective but discourages it for women under the age of 35.
“I’m cautious to recommend diets of any type, particularly intermittent fasting, for teenage women and women in their 20s and early 30s,” she said.
“It can be very difficult for hormones in women which is a concern if they are child-bearing, or it can interfere with women’s menstrual cycles.
“I’m also cautious of the idea of skipping a meal. I don’t find people focus on the quality of food in that short eating window and it can put your body into starvation mode. You’re reducing the amount of nutrients you are getting, or you might not be getting enough protein or carbohydrates.”
Other diets include:
Ketogenic, a high-fat, low carbohydrate diet that forces the body to burn fats rather than carbohydrates. Risks include low blood pressure, kidney problems, constipation, nutrient deficiencies and increased risk of heart disease.
Paleo, which mirrors the Stone Age diet by focusing on lean meats, fish, fruits, vegetables, nuts and seeds and removes the agricultural and industrial processing of foods. Pitfalls can include a reduction in vitamin D and calcium.
Mediterranean, which consists of whole grains, fruits, vegetables, seafood, beans and nuts. This can help healthy ageing and prevent cardiovascular diseases, but can lead to lower levels of iron or calcium, and weight gain from fats in olive oil and nuts.
Dash, which focuses on vegetables, fruits and whole grains and includes low-fat dairy products, fish and poultry but limits salt, sugar and saturated fat. It can lower blood pressure and the risk of heart disease, and help people lose weight. This diet requires meals to be carefully prepared and can lead to gas or bloating.
Ms Wight urges people to seek professional advice to decide on their nutrition plan.
“What we really need is the opposite of diet. You don’t need to cut things out of your diet, you just need to emphasise getting more of the good stuff into our diet,” she said.
“We need to see the pros and cons of certain food groups and know how much of each we should have and how much our body is really enjoying.”
