We all want a simple, straightforward answer to the question: what’s the healthiest diet? What diet will help you improve your health, manage your weight, feel energised and avoid disease? When you think about it, that’s a lot to ask from your dietary choices…

And the simple answer is this: there is no one-size-fits-all approach to nutrition. Sorry to break it to you. What works for one person won’t work the same for the next. Every body has unique needs and preferences, and performs better following individual dietary choices and preferences.

However, there are some diets which are better than others when it comes to supporting general health and managing weight. So let’s begin by looking at the diets which aren’t the healthiest choices to stick to…

1. Keto.

While the ketogenic diet has been all the rage for the past few years, it was originally designed to manage epilepsy in affected children, amongst other very specific medical conditions. Since then, it’s been sensationalised for its ability to “promote weight loss”, however it’s not quite as simple as this.

The keto diet requires you to get the majority of your daily energy intake from fats, with a moderate intake of protein and a very low carbohydrate intake. Generally, the macro split will be divided into 70-80% fats, 10-20% protein, and just 5-10% of energy from carbs. Since carbohydrates carry water with them when you consume them, most of the weight lost in the initial few days or weeks when you begin the keto diet is simply water weight. When you cut the carbs, you stop retaining water too, so naturally the number on the scales will drop too. However, as soon as you stop adhering to the strict keto diet and begin reintroducing carbs, that water weight comes right back, meaning any weight loss on the keto diet is very temporary and unlikely to be sustainable.

Similarly, carbohydrates are actually incredibly important for your overall health. If you’re not eating enough carbs, you’re depriving your body of its preferred source of energy, often leaving you feeling lethargic and fatigued. This can also result in the “keto flu”, with symptoms including low energy, brain fog, headaches, moodiness, nausea and constipation.

The restrictive nature of the keto diet also leaves you at risk of nutrient deficiencies, and encourages an overconsumption of saturated fats found in “keto-friendly” foods like bacon, butter and cream. But while saturated fats may fit the macro profile of the diet, they’re not beneficial for your overall health, and swapping whole grains and starchy carbohydrates out to replace them with saturated fats is not a healthful switch.

You’re missing out on all the abundant micronutrients and minerals found in vegetables and fruits and wholegrains - and the fibre you need to nourish your gut and support digestion - and increasing your levels of “bad” cholesterol instead.

The keto diet has been linked to an increased risk of heart disease, low blood pressure, kidney problems, digestive discomfort and nutrient deficiencies, and is highly unsustainable in the long-term. It has also been associated with increased risk of disordered eating thoughts and behaviours, due to its overly prescriptive and restrictive nature.

So don’t believe the marketing hype. While the keto diet may be appropriate for select people with particular health conditions under the guidance of a health professional, it’s not the healthiest or best diet for most.

2. Paleo.

The paleo, or Paleolithic, diet is designed to encourage foods which our ancestors once consumed in the cavemen days, with the idea that these foods supported our genetics and our body’s natural requirements. A paleo diet emphasises all the foods which would have been accessible for hunter-gatherers in the past, including fish, vegetables, meat and other unprocessed foods. It requires limiting whole grains, dairy products, legumes, and processed foods, claiming these foods promote disease and other health complications.

However while that may sound healthy initially, it again leaves you at risk of nutrient deficiencies - particularly calcium and vitamin D, which are essential for bone health. Instead, it encourages overconsumption of protein and saturated fats, again due to the emphasis on large quantities of meat, which can cause kidney and heart problems, and worsen the risk of some cancers.

Again, the limitations on carbohydrate consumption are not health-promoting, and the exclusion of whole grains and legumes can lead to low energy levels, nutrient deficiencies (such as B-vitamin deficiencies), and low fibre intake, causing digestive and gut health problems. Whole grains and legumes are incredibly nourishing and healthy, and should be included as part of a balanced diet, so to exclude them is not beneficial to most people’s health. 

While it may be a positive to reduce your intake of highly-processed foods, and focus more on eating vegetables, lean proteins and less-processed options, doing so by excluding key food groups and nutrients is not the best way to achieve general health and weight balance, meaning the paleo diet is not the best or healthiest diet available.

3. Detoxes.

Whether it’s the lemon detox diet, a juice cleanse, or extended periods of fasting during which only fruit, vegetables, water and specific liquids are permitted, detoxes claim to “cleanse” and detoxify the body of toxins, and aid in rapid weight loss. Many of these alleged benefits come from the fact you’re giving your digestive system a break from processing solid foods, allowing you to feel more energised and revitalised post-detox.

However, in reality, often the reverse is true. It’s incredibly difficult to meet both nutrient and energy requirements while you’re on a detox or cleanse diet, and this often leads to significant lethargy, fatigue and low energy levels.

Many detoxes also claim to “restart your metabolism,” when in actuality they risk slowing down your natural metabolic rate, as your body enters “survival” mode and tries to store as much fat as possible in the face of seemingly endless famine. In other words, your body is no longer certain when it will be fed its next meal, so it slows down your metabolism in order to store fat in the event it’s not getting enough energy to support normal function. While these types of diets claim to support rapid weight loss, it’s mostly water weight that you’re shedding. This means, similarly to the keto diet, as soon as the detox is over, you can expect to regain most or all of that weight very quickly.

Aside from the fact that detoxes deprive your body of crucial nutrients and energy, and allow little or no fibre consumption at all, the biggest problem with detoxification diets is this: your body has natural detoxification processes (with the liver and kidneys being some of the key organs involved in these), and does not require any additional manufactured detoxifying practices. Your body filters out the “nasties” all on its own, so to attempt a detox diet is actually causing far more harm than good. You’re only putting your body at risk of electrolyte imbalances, digestive problems, dehydration and other health complications.

What do these diets all have in common? 

When we look at these “trendy” fad diets, there are a few glaring red flags which they all have in common.

Firstly, they each promote restriction. Instead of emphasising inclusion, and focusing on the abundance of nutritious foods you should aim to include in your regular diet, these fads instead push which foods you shouldn’t consume - often with little or no scientific evidence behind these limitations too.

We know that with any type of restriction or deprivation, your body biologically rebels. If you attempt any diet which requires you to cut out certain foods or food groups, you’ll likely experience heightened cravings for that particular food, to the point where you feel the need to binge on it in order to compensate for the fact it’s “forbidden”. This is exactly why so many diets fail: deprivation doesn’t lead to success, it promotes a negative relationship with food, and an over-compensation for those foods you’re attempting to eliminate.

These fad diets all push food rules and fears too, labelling foods as “good” and “bad”, when we know no food exists on a binary spectrum. By excluding foods and food groups, these diets encourage a black-and-white approach to food, whereby you begin to associate foods with moral value, and judge yourself according to your food choices. This is a recipe for a bad relationship with food, and often contributes to disordered eating thoughts and behaviours. The reality is, foods are neither good nor bad. They’re simply foods. Absolutely, some foods are more nutrient-dense than others, but there is room for all foods in a healthy and balanced diet, and any fad claiming otherwise is unsustainable and unhealthy for both your body and your mind.

Instead of adopting a scarcity or restrictive approach to eating, a balanced diet emphasises inclusion and abundance. The more diversity and variety you can achieve in your diet (particularly from plant-based foods), the healthier you’re likely to be, and the more you’re able to sustain a healthy way of eating.

So what is the healthiest diet after all?

While there’s no one-size-fits-all approach to nutrition, the Mediterranean diet is realistically the optimal model for a healthy and balanced diet. Particularly given the Mediterranean diet is more of a lifestyle model than a “diet”, it emphasises inclusion, promoting an abundance of vegetables, fruits, nuts and seeds, legumes, fish and olive oil. It suggests a moderate intake of dairy foods, and a small consumption of red meats. It recommends limiting high-sugar foods, refined carbohydrates and saturated or trans fats. 

This way of eating is common in countries like Spain, Greece and Italy - places which are widely renowned for their relationships with food, and the pleasure they derive from the eating experience. Mediterranean countries tend to focus on enjoying food and drink (including wine!) with family and friends, and cultivating an eating experience which involves mindfulness, pleasure and moderation. There’s no place for counting calories, but instead people are encouraged to tune into internal signals and cues to know when they’ve eaten enough, and to honour their body’s needs and cravings for certain foods. Exercise is also encouraged, again in moderation, with an emphasis on movement which brings joy and is sustainable in the long-term.

What are the benefits?

The way in which food is eaten in the Mediterranean diet is crucial to the benefits it offers. The social aspect of food, and its ability to foster connection and pleasure, has been shown to help reduce inflammation and stress. How you eat can have just as much of an impact on your health and wellbeing as what you eat, so eating in a balanced, inclusive, positive way allows you to reap endless health benefits as a result. This also makes mindful eating and honouring your body’s hunger signals much simpler, meaning you’re less likely to binge or overeat as a result of a restrictive mentality around food.

Similarly, the type of foods promoted by the Mediterranean diet are anti-inflammatory, and support general physical and mental health. The strong emphasis on healthy fats and omega-3 fatty acids has a plethora of benefits to brain health, heart health, weight management, satiety, joint health and more. 

Research has found the Mediterranean diet may:

• Reduce your risk of cardiovascular complications and disease

• Reduce your risk of dementia and slow down age-related cognitive decline, though more research is needed in this area

• Protect against some cancers and health conditions including type 2 diabetes

• Reduce inflammation

• Support mental wellbeing

• Help with weight management

• Help to promote satiety

• Reduce symptoms of arthritis and joint pain

• Reduce the risk of stroke (in women)

• Support general physical and mental health

Sounds pretty good, right? The key takeaway is that there’s no singular approach to eating on the Mediterranean diet. As each Mediterranean country and culture enjoys its own ingredients and foods, there is room for flexibility to allow each individual to eat foods which make you feel your best while following this “diet” or lifestyle pattern. Focus on inclusion and diversity of food, rather than exclusion and food rules or restrictions, and eating more healthy fats, fresh whole foods like vegetables and whole grains, and lean proteins like fish, and you’re well on your way to eating in line with the “healthiest” diet available to us.