Fad diets come and go but these rules for sustainable weight loss will stand the test of time.

Weight loss is a thorny issue. For the genetically blessed few, shedding pounds can seem effortless. But for most of us, losing weight and keeping it off is an eternal uphill struggle: just when you’re making inroads into your waistline, a holiday, night out or stress-inducing deadline can derail your good work.

Fad diets and miracle supplements that promise beach body abs can appear tempting at times like these, but in reality any nutrition plan that promises dramatic results, often without substantial scientific evidence to support its claims, is at best unsustainable, and at worst downright dangerous.

Sustainable weight loss, by contrast, takes patience and perseverance. No quick fixes, no fads, just proven methods that have been practised for decades. Here, with the help of the Huel nutrition team, we’ve dug into the very latest fat loss research to bring you our golden rules for safe, sustainable weight loss. Chisel them in stone and nail them to your fridge.

1: Do your homework

Your body is a temple – what you put into it matters. Often fad diets promote the merits of a certain type of food while neglecting to mention everything they cut out.

Take, for example, the “juice cleanse”, likely popularised on your TikTok timeline. “The juice cleanse diet promotes rapid weight loss and ‘detoxification’ by consuming only fruit and vegetable juice, often for a week or two,” explains Jessica Stansfield RNutr, junior nutrition manager at Huel.

Why is this a problem? “Because it drastically oversimplifies detoxification and fundamentally ignores the fact that our bodies have their own natural detox systems, such as the liver and kidneys, which are compromised when we don’t eat a balanced diet,” says Stansfield. So, before you jump on the latest diet craze on social media, take a moment to investigate its pros and cons so you know you haven’t bitten off more than you can chew.

2: Consume healthy fats

The archetypal Mediterranean diet – rich in vegetables, fruit, whole grains, fish, nuts and, crucially, olive oil – has long been associated with a healthy lifestyle. It’s best known for helping prevent heart disease and reducing inflammation, but numerous studies indicate its high plant-based unsaturated fat content is similarly effective at promoting weight loss.

One systematic review of five studies, published in 2016, found the Mediterranean diet resulted in greater weight loss after one year than a low fat diet, and produced similar results to that of a low carb diet. Another 2020 study over a 12 month period noted that a higher adherence to the diet led to double the likelihood of weight loss maintenance.

In other words, the closer you stick to a diet like the one enjoyed in countries hugging the Med, such as Italy and Greece, the better your chances are for keeping the weight off.

3: Swap out, don’t cut out

The word “diet” often conveys the notion of restriction or denial. In truth, it comes from the Greek term 'diatita', meaning “a way of life”. That, says Stansfield, is a key point of difference. “A helpful tip when starting a new diet,” she says, “is to shift your mindset from focusing on all the things you can't have to all the great stuff you can enjoy.”

For example, rather than simply eliminating a packet of crisps and can of pop from your lunchtime meal deal, consider making positive swaps. “Add some dried fruit and nuts, popcorn or a cocoa-flavoured protein ball to your shopping basket instead,” suggests Stansfield.

4: Increase protein, decrease carbs

It’s worth noting at this point that protein is not a halo food and carbs are not the enemy. Striking the right balance between the two, however, can provide a raft of nutritional benefits for both performance and weight loss.

“A high-protein diet drives multiple benefits,” agrees Stansfield. “Protein's satiating effect helps delay hunger between meals, while its high thermic effect [the amount of energy it takes your body to digest, absorb, and metabolise the food you eat] triggers a higher metabolic rate that can promote greater weight loss throughout the day.”

In fact, one study suggests that diets containing between 1.2-1.6g of protein per kilogram of bodyweight, or at least 25-30g of protein per meal, resulted in “improvements in appetite, body weight management and cardiometabolic risk factors”.

At the same time, low carb diets (in favour of healthy fats and quality protein) have proven to be especially effective at maintaining weight loss. One extensive meta analysis of 53 studies, involving more than 68,000 participants, found that low carb diets resulted in significantly more weight loss than low fat diets.

A three-egg cheese omelette with a Greek side salad is a prime example of a high-protein, high-fat meal you could try in place of toast or cereal, suggests Stansfield.

5: Get more sleep

One lesser known, yet equally vital ingredient, for sustainable weight loss is sleep. “Sleep should never be underestimated,” says Stansfield. “Insufficient sleep can disrupt the delicate balance of hunger and satiety hormones, resulting in a heightened appetite and an increased risk of overeating.”

While the NHS doesn’t set a recommendation for how much sleep us Brits should aim for, the Centers for Disease Control and Prevention (CDC) in the US stipulates that adults aged 18 to 60 should get seven or more hours of sleep each night.

In a joint statement from the American Academy of Sleep Medicine and Sleep Research Society in the US, it’s noted that any less than seven hours on a regular basis is associated with adverse health outcomes, including “weight gain and obesity, diabetes, hypertension, heart disease and stroke, depression, and increased risk of death”.

6: Practise portion control

It might sound over-simplistic, but the size of your dinner plate can heavily influence the size of your appetite. Large plates, for example, can make food appear smaller, often leading to overeating. One 2012 study found that people who ate from a large bowl consumed a whopping 77% more pasta than those dining with a medium-sized bowl.

Before you swap out all your fine china, it’s worth bearing in mind that mindful eating techniques, such as chewing slowly, savouring your food and never consuming to a point of more than 80% full – as adhered to in Japan, a population famed for its longevity – can also help prevent overconsumption.

7: Exercise regularly

Combined with a balanced diet and adequate sleep, regular exercise can help tip the weight loss scales in your favour. “Participating in physical activity expends calories, and when your calorie expenditure exceeds your calorie intake, a calorie deficit is created, resulting in weight loss,” explains Stansfield.

But how much and what type of exercise? Studies suggest that any activity performed at a high enough intensity to trigger the afterburn effect (also known as EPOC – excess post-exercise oxygen consumption) increases your body’s metabolic rate, promoting the maintenance of body mass.

Both resistance training with compound movements and high-intensity interval training at or above 50-60% of your VO2 max have proven to stimulate this EPOC reaction – possibly lasting for up to 38 hours in some cases.

8: Don’t overcompensate post workout

Yes, regular exercise can help shift you into a calorie deficit. Yet it’s not a silver bullet for long-term sustainable weight loss. “The term, ‘you can’t out-train a bad diet’ is absolutely true,” says Stansfield. Chasing every workout with a supersized helping of junk food is the epitome of unsustainable weight loss (for both your waistline and the planet).

Instead, look to consume an even balance of quality protein, healthy fats, and low glycemic index carbohydrates (such as oats or whole grain pasta) in your post-workout meal.

9: Experiment with intermittent fasting

Intermittent fasting (IF) exists in many forms. The 16/8 method involves limiting your calorie intake to just eight hours per day. The 5:2 method restricts your daily intake to just 500-600 calories twice per week. Then there’s simply skipping breakfast, a type of intermittent fast plenty of us practise unwittingly when we’re running late for work.

Restricting your daily calorie intake is effective at promoting sustainable weight loss because it helps tip you into a natural calorie deficit (presuming you don’t overcompensate at dinner). Studies suggest this form of temporary fast is also more sustainable than crash dieting.

In a systematic review published in 2020, all 27 IF trials investigated led to weight loss of between 0.8 - 13%, along with “no serious adverse events”. These positive results spanned trials lasting from just two weeks up to one year. Another study suggested the 16/8 method of IF, when followed in conjunction with resistance training, can reduce fat mass while preserving muscle mass.

That said, there are certain groups of people, especially those who are diabetic and liable to wild fluctuations in blood sugar levels, who should exercise caution when fasting. As with all our advice, it’s best to speak to your medical professional before undertaking a new diet.

10: Set realistic expectations 

“To lose 1lb (0.45kg) of fat per week you need to achieve a calorie deficit of around 500 kcal per day,” recommends Stansfield. Any more and you’ll risk crashing so go slow and steady.

Remember, to maintain any successful weight loss it’s essential to embrace a lifestyle change, rather than a short-term crash diet. “Avoid the temptation to drastically cut your calorie intake within a short period, and set your sights on the long run,” she adds.

Words: Sam Rider