Weight loss diets reviewed

Diets have been a part of human history for centuries. The first book on our eating habits, The Art of Living Long , was published in 1558. But our ideas around dieting for weight loss first emerged in 1825 when Jean Brillat-Savarin wrote about the benefits low-card diets for shedding weight.

Since then, many diets have been developed. While some of them can support weight loss, others are no more than fads. But how can you tell the difference between an effective, sustainable weight loss solution and trending weight management ideas? We break down the pros and cons of 5 weight loss diets.

• Vegan diet
• Low-fat diet
• Atkin's diet
• Paleo diet
• 5:2 diet

If you decide to go vegan, you won’t be alone in making that decision. In the UK, 2.5 million people are plant-based. This number increased by 1.1 million between 2023 and 2024.¹

More and more people are interested in cutting out animal products from their diets. And the reasons are varied. For some, it’s a decision to honour their ideas about respecting all life forms but for some, their choice to move away from animal-derived products is health driven.

Vegan diets have been linked to weight loss and improved blood sugar control. So it's worth making the change and cutting out meat and dairy products from your diet²

Pros

Nutrient-dense: A vegan diet is typically rich in fruits, vegetables, whole grains, and legumes, providing essential nutrients like fibre, vitamins, and minerals. This can promote better heart health and reduce the risk of chronic diseases like hypertension and diabetes.

Lower calorie density: Vegan diets tend to be lower in calories due to the high intake of low-calorie, high-fibre foods, which can lead to weight loss without calorie counting.

Environmental benefits: A plant-based diet is often associated with a lower carbon footprint, making it a more sustainable choice for the planet.

Cons

Nutrient deficiencies: Vegan diets can sometimes lack essential nutrients such as vitamin B12, iron, calcium, and omega-3 fatty acids, requiring careful planning or supplementation.

Social challenges: Eating out or finding vegan options in certain regions or social settings can be challenging.

There are lots of low-fat diets. Keto, the Mediterranean diet and DASH are only some of the eating routines you can adopt that focus on reduced fat intake.

Although fats are essentially for healthy human bodies, we only need a limited amount of them. Some foods raise the levels of bad cholesterol (low-density lipoproteins in our blood). This can lead to the build-up of plaques in arteries.

Pros

Heart health: Low-fat diets have been linked to improved heart health, particularly for individuals with high cholesterol or a history of heart disease. Reducing saturated fats can lower LDL (bad) cholesterol.

High in carbohydrates: This diet allows for more carbohydrates, which can be beneficial for those who enjoy starchy foods like potatoes, rice, and whole grains.

Cons

Risk of overeating refined carbs: When fats are restricted, people may overcompensate by consuming more refined carbs and sugars, which can lead to weight gain and increased risk of insulin resistance.

Sustainability: Low-fat diets can be difficult to sustain long-term, especially if they restrict fats like those found in nuts, seeds, and avocados, which are beneficial for overall health.

The Atkin’s diet was developed at John Hopkin’s Hospital, USA, as an alternative to the keto diet. Like the ketogenic diet, it encourages people to reduce their carb intake but it is less strict.

People who use it to manage their weight eat 10 grams of carbs per day and are encouraged to eat high-fat foods. It’s been over 20 years since the diet was created. So how does it stack up to more modern weight loss approaches?

Pros

Rapid weight loss: Low-carb diets like Atkins often lead to rapid weight loss, especially in the initial stages, as the body sheds water weight and begins to burn fat for energy.

Improved blood sugar control: This diet can help stabilize blood sugar levels, making it particularly beneficial for individuals with type 2 diabetes or insulin resistance.

Cons

Restrictive: Atkins and similar low-carb diets can be challenging to follow long-term due to the strict limitations on carbohydrates, including fruits, grains, and some vegetables.

Potential nutrient deficiencies: Low-carb diets may result in insufficient intake of important nutrients like fibre and certain vitamins and minerals found in carbohydrate-rich foods.

The paleo diet or the cave man diet. It takes influence from the ways our ancient hunter-gather ancestors would have eaten. Whole foods, lean meat and proteins like eggs are staples of this diet.

The approach may seem prehistoric, it is linked to a lower risk of cardiovascular disease, type 2 diabetes, colorectal cancer, obesity and stroke. It can also help improve your metabolic health which is strongly linked to your ability to manage your weight.

Pros

Focus on whole foods: The Paleo diet emphasizes whole, unprocessed foods, such as lean meats, fish, fruits, and vegetables, which can improve overall nutrition

Antiinflammatory: By eliminating processed foods and refined sugars, the Paleo diet may help reduce inflammation in the body.

Cons

Elimination of food groups: The Paleo diet excludes entire food groups such as grains, legumes, and dairy, which can lead to nutrient deficiencies if not carefully managed

Costly and time-consuming: Preparing whole foods and sourcing grass-fed meats or organic produce can be expensive and time-consuming.

The 5:2 diet is a type of intermittent fasting . It involves eating a normal healthy diet for 5 days of the week and restricting your calorie intake for 2.

It is associated with weight loss because the practice forces your body to tap into its fat stores for energy.

Pros

Flexibility: The 5:2 diet allows for flexibility, as you can eat normally five days of the week and restrict calories only on two days, making it easier to adhere to than more restrictive daily diets.

Weight loss: By reducing calorie intake over the course of a week, this diet can lead to gradual and sustainable weight loss.

Cons

Hunger on fasting days: Many people find fasting days difficult, and the associated hunger can make the diet hard to stick to long-term.

Not suitable for everyone: Fasting may not be appropriate for those with certain medical conditions, such as diabetes or eating disorders.