Thinking of a quick fix to get in shape this summer? Maybe you should reconsider, experts say.
Eating just 800 calories a day, eating only baby food, and consuming fruits and vegetables for what is called a juice detox are just a few of the most popular crash diets.
They have made a name for themselves because they promise enormous and fast weight loss.
However, nutritionists say these supposed “miracle diets” only deliver short-term results — and many followers end up weighing more than before.
According to experts, possible side effects include lack of energy, lack of concentration, hair loss and skin problems.
Here, nutritionists reveal the seven crash diets they would absolutely avoid.
Drastic calorie restriction can help not only with fat loss, but also with muscle loss. This can have long-term effects on your metabolism, nutritionists warn
Very low calorie diets
Severe calorie restriction for quick weight loss is a popular crash diet – but it can lead to serious health problems.
This involves consuming less than 1,000 calories per day, with some plans including further reductions in calorie intake, such as the 800-calorie diet.
But very low-calorie diets can lead to a lack of vital nutrients and the onset of fatigue and metabolic slowdown, experts say.
Clinical nutritionist Lee Holmes, author of the Supercharged Food book series, said, “It can lead to nutrient deficiencies, as rapid weight loss is often associated with severe calorie restriction, which can result in insufficient intake of essential nutrients.”
“This can lead to deficiencies in vitamins, minerals and other essential nutrients necessary to maintain overall health.”
Can Ozempic help with long-term weight loss?
While it’s not about cutting calories or eating restrictive foods, the weight loss vaccine is arguably used as a “quick fix.”
The weight-loss drug is adored by Hollywood stars, and semaglutide injections like Wegovy and Ozempic have been praised for helping tackle the fight against obesity.
However, not all health experts agree that it is the solution to weight loss.
“Ozempic does nothing to address the root cause of weight gain,” says Miss Pearson.
She said, “There are a lot of clinics and doctors that hand it out without giving people nutritional advice or telling them how to control their weight long-term.” It’s just a quick fix.
“People will just quit and go back to old habits and put back the weight that they lost.”
Severe calorie restriction can also trigger the unwanted side effect of muscle loss.
“When people really cut calories and don’t eat enough protein, they tend to lose not only fat, but muscle as well,” says Kim Pearson, a nutritionist at Harley Street in London.
“If you’re not consuming enough protein, which is key to supporting muscle mass, you will experience a decline in your muscle mass.”
“It looks like you’re losing weight on the scale, but you slow down your metabolism, your body’s ability to burn calories decreases, and once you start eating normally again, you’re more likely to gain it back.”
Miss Pearson warns that both the 800-calorie diet and the 5:2 diet — which eats 800 calories a day twice a week — make it difficult to get all of the essential nutrients.
She said, “If you’re going to cut your calorie intake that far, you have to be extremely knowledgeable and make sure you’re continuing to get the nutrients the body needs.”
Those on a low-calorie diet may also end up eating more processed foods and convenience foods, like sandwiches, rather than cooking from scratch because it makes calorie counting easier.
meal replacement shakes
Replacing food with meal replacement shakes has been popular with dieters for decades.
Even the NHS is rolling them out and offering them to type 2 diabetes patients to help them lose weight – with some calling the results “life-changing”.
While such shakes can be low in calories, leading to rapid weight loss, they can also slow your metabolism and lack essential nutrients.
Nutritionists argue that while some claim they’re packed with nutrients, the nutrients are in synthetic form — meaning they’re of lower quality than those found in food and can be harder for the body to absorb.
For this reason, Miss Pearson would not advise people to use meal replacements such as SlimFast shakes now being promoted by rapper Big Narstie.
“I don’t like low-quality, low-calorie meal replacement shakes at all.” “Not all meal replacements are created equal,” she said.
“There are some that are fine — these are usually the ones that are prescribed by doctors and nutritionists and are protein-based.”
Mis Pearson added, “The nutrients they provide are usually in synthetic form, so these are not the forms of nutrients that are found naturally in foods, but rather low-quality synthetic supplements.”
“A lot of them are also highly processed and contain thickeners, emulsifiers and preservatives.”
detox diets
Detox diets are based on the idea that “toxic waste” must be removed from the body in order to lose weight or stay healthy – a concept experts say is nonsense.
Popular approaches include consuming only fruit and vegetable juices, only liquids, or a lemon drink for a set period of time—from a few days to weeks.
However, as with other crash diets, detoxification often fails to get the amount of nutrients your body needs.
These diets “often lack essential nutrients, protein, and fiber, which can lead to nutrient imbalances, low energy levels, and gastrointestinal problems,” Ms. Holmes says.
Although lemon juice is a good source of vitamin C by itself, Ms. Holmes says it’s not enough.
Nutritionists say not all juice cleanses are sustainable or safe. Most of the weight loss on such diets is due to dehydration, which can lead to weakness, headaches and even fainting, experts say
She said, “Relying solely on it for an extended period of time can lead to severe nutritional deficiencies and under-calorie intake.”
In addition, such detox diets are often filled with sugar.
Miss Pearson said, “Juice detoxes contain a surprising amount of sugar.”
“Even if the sugar comes from fruit, it can dysregulate your blood sugar levels.”
“Yes, fruit is healthier than a Mars bar, but once it’s in the gut and absorbed by blood sugar, the body can’t tell the sugar in a Mars bar from the sugar in a juice.”
Most of the weight loss on such diets is due to dehydration, which can lead to weakness, headaches and even fainting, experts say.
Atkins diet
Reportedly loved by celebrities like Kim Kardashian, Jennifer Aniston and Rob Lowe, the Atkins diet involves eating lots of protein and fat while cutting back on carbs.
Developed by American physician and cardiologist Robert Atkins in the 1960s, the diet aims to put the body into a state known as ketosis.
This is a metabolic state that occurs when the body switches from burning carbohydrates to burning fat for energy.
Only 5 to 15 percent of daily caloric intake for those following the diet comes from carbohydrates, compared to the 50 percent recommended by most guidelines.
Although this diet can help you lose weight, experts say it can have long-term health effects, including an increased risk of heart disease.
Ms Holmes said: “Carbohydrates are a vital source of energy for the body and severe restriction can lead to initial weight loss.”
“But the long-term health effects of eating large amounts of saturated fat and animal protein are a cause for concern, as they can increase the risk of heart disease, kidney problems and nutrient deficiencies.”
keto diet
Just like Atkins, keto is a low-carb, high-fat diet that aims to boost ketosis — when the body burns fat for energy rather than carbs.
Celebs like Gwyneth Paltrow, Megan Fox and Kourtney Kardashian are said to have tried it.
But many nutritionists do not particularly praise this.
“Once we demonize an entire food group, food is no longer our friend,” says Ms. Holmes.
She said, “Carbs are not the enemy and everything, including carbs, should be eaten and enjoyed in moderation.”
“Not to mention that by cutting out carbohydrates, we forego the benefits of many of the nutrients we need to support our gut function and immune system.”
Followers of the keto diet run the risk of missing out on important prebiotics found in root vegetables, seeds, and fruits.
Ms Holmes added, “Unfortunately, many keto enthusiasts skip prebiotic-rich vegetables for their carbohydrate content, which isn’t good news for a healthy and diverse gut.”
“I see a lot of people in my clinic who have gone ketogenic and are now suffering from gut issues.”
baby food
The bizarre fad of eating baby food instead of lunch and breakfast first gained popularity in 2010 when rumor had it that actress Jennifer Aniston lost seven pounds in a week.
The original diet consisted of having a jar of baby food at breakfast and lunch – replacing your normal meals – and having a “normal” dinner.
Baby food can contain anywhere from 20 to about 120 calories. So when you eat jars of baby food, you lose weight because you are consuming significantly less food and nutrients
Over a decade later, the diet is still rampant on TikTok, with some followers only eating baby food to lose weight.
The jars can contain anywhere from 20 to 120 calories, so this is an extremely low calorie diet.
Ms Holmes said: “While baby food can be nutritious, it is not designed to meet the nutritional needs of adults.”
“It’s low in calories, protein, and fiber, and lacks the variety of nutrients needed for optimal health.”
“This diet can lead to nutrient deficiencies, muscle wasting, and difficulty with portion control and long-term adherence.”
cabbage soup
Designed to help you lose weight fast, this liquid cabbage soup diet is taboo for nutritionists.
The cabbage soup diet has been a celebrity favorite since the ’80s. For a week, dieters can eat almost nothing except homemade cabbage soup and a few pieces of fruit.
This leads to extreme weight loss with some losing 10 pounds in just a week. However, nutritionists say it also affects your health.
However, experts believe that most of the weight lost from the monotonous diet is simply due to loss of what is known as water weight and is likely to regain once you start eating normally.
“The cabbage soup diet is deficient in protein, healthy fats and essential nutrients, and is not sustainable or healthy over the long term, leading to potential nutrient deficiencies and negative impacts on overall health,” says Ms Holmes.
Experts believe that most of the weight lost from the monotonous cabbage soup diet is just water weight and is likely to regain once you return to eating normally
She added, “It’s very restrictive and monotonous, making it difficult to sustain for long periods of time and can lead to boredom, cravings and deprivation.”
The extreme lack of calories can lead to energy loss, fatigue and nutrient deficiencies, experts say.
And the unsustainable diet doesn’t help you lose weight in the long run.
Miss Pearson said, “Crash diets encourage an all-or-nothing mentality.”
“People crash diet before a vacation, then go on vacation and then go crazy because they’re deprived.”
“Once they arrive at the breakfast buffet, they just want to eat whatever comes their way.”
Many of these fad and crash diets are unsustainable and unhealthy.
To lose weight in a healthy and sustainable way, the British Dietetic Association (BDA) recommends setting a realistic weight loss goal – say 1 pound a week – and creating an action plan to stay on track.
Eating balanced meals — filling your plate so that half is salad and vegetables, a quarter is lean meat, fish, eggs, or tofu, and the last quarter is starchy foods like potatoes, brown rice, or pasta — is key .
It’s also important to limit sweet, fatty, and salty snacks, according to the BDA.
If you don’t feel like eating air for two weeks before your vacation, experts say there are sustainable ways to lose weight, such as cutting out sugar, refined starchy carbs and processed foods.
Tips for losing weight without crash diets
Nutritionists are urging people to take a healthy and sustainable approach to losing weight.
“Dieting doesn’t have to be extreme to get results,” says nutritionist Kim Pearson.
She added, “Just focus on cutting out sugar, refined starchy carbs, processed foods, eating quality lean protein, lots of vegetables and salads, and a moderate amount of healthy fats.”
Nutritionist Lee Holmes shares her simple tips for losing weight.