Why diets don’t work

Unfortunately, when it comes to diets, we’ve all been told a lie. As appealing as it sounds to obtain rapid weight loss via a short-term dietary intervention, the reality is – diets don’t work in the long run. Here I’ll share why diets don’t usually lead to long-term weight loss, and what a sustainable approach to weight management looks like instead.

What do we mean by diets?

Diets come in all shapes and sizes. You’ve probably heard of the Atkins diet, the 5:2 approach, the Weight Watchers’ program, or the more extreme celery juice diet. Essentially, all of these diets are designed to restrict the calories you consume through a range of different techniques.
Some dietary approaches are more realistic than others, but studies show that diets promoting either extreme calorie restriction or the removal of core food groups, don’t usually result in long-term weight loss.

Why aren’t diets successful in the long term?

Diets are usually unsuccessful in the long term due to the inability of people to adhere to such restrictive dietary approaches. Such unrealistic diets can result in compensatory overeating, binging, or choosing high-calorie foods as ‘treats’ after following a strict diet. Such approaches also aren’t realistic in such an obesogenic environment. The inability to stick to highly restrictive dietary patterns is not the result of a lack of willpower.

it’s just simply unachievable for most people to adhere to strict diets as these create cycles of deprivation and binging – and can severely affect socializing and other cultural norms involving food choices. Take the famous Weight Watchers program – whilst many people show initial weight loss, studies show that within a year of stopping such programs, participants can end up weighing more than before they began the dietary intervention. This can lead people to feel demoralized and as if they have failed.

But there are actually very real physiological factors at play – which can make long-term weight loss hard to achieve. Similarly, such diet approaches can set up an unhelpful narrative around food – by labeling certain foods as bad, or even ‘sins’. It’s more effective to consider overall eating patterns and to relabel foods as ‘everyday foods’ or ‘sometimes foods’.

How does the body respond to extreme calorie restriction?

When you enter a period of extreme caloric restriction, your body starts to compensate. This process is known as adaptive thermogenesis. It’s essentially a survival mechanism that guards against starvation. Here, your body reduces its energy expenditure to preserve precious calories. This happens both during exercise and at rest. This means that even though you are eating less, you are also using less energy – so it’s harder to achieve a negative calorie balance. Secondly, your body also instinctively increases your appetite to encourage you to eat more. So, this can make it even harder to stick to restrictive dietary plans.

What does sustainable weight loss mean?

Sustainable weight loss approaches aim to achieve slow and steady weight loss, rather than rapid losses followed by substantial gains. Whilst it can be satisfying to see the noticeable weight reductions that temporary diet plans can bring, it’s ultimately more demoralizing to deal with the weight regains that occur further down the road.

Instead, a sustainable weight loss plan is designed to provide you with a realistic long-term approach to eating, which is flexible, achievable, and easy to adhere to over time. Such approaches don’t require you to cut out any particular food group (such as carbohydrates, proteins, or fats) and can be tailored to your own personal needs and likes.

Any successful weight loss plan will however need to involve a calorie deficit. This is the basis of weight loss – consuming fewer calories than you use. Whilst it’s tempting to think you can just eat the same and do a bit more exercise, studies have shown that physical activity alone isn’t the best approach for long-term weight loss.

This is because people tend to underestimate just how much physical activity is required to utilize relatively small amounts of calories. Additionally, physical activity can increase your appetite, leading to a fairly natural increase in food consumption following prolonged exercise.

This doesn’t mean that physical activity isn’t useful for weight management – after all, it can increase your daily energy expenditure. In addition, resistance exercise involving the use of your muscles against a force, can over time, increase your lean muscle mass. Having more muscles can increase your basal metabolic rate. This means you’ll expend more calories when at rest, helping to tip your daily energy balance in a positive direction.

But overall, a daily calorie deficit of around 500 calories, is considered by most experts to be a successful, sustainable weight loss strategy that will lead to modest weight reductions of 1-2 pounds a week. These changes add up over time and can lead to long-term weight loss success.

How to cut 500 calories a day?

It can help to keep a food diary for a week or so to get a feel for where you might be ‘spending’ some unnecessary calories. Many people will find that it’s not usually the meals that are contributing to an excess, but more likely it’s a combination of drinks and snacks.

For example, if you regularly enjoy a takeaway latte, with syrups and creams you can easily be adding 300-500 calories per day. Similarly, a small glass of wine can be around 140 calories, and many shop-bought pastries and cakes can get you up to around 500 + calories.

So, make the switch to a flat white or americano with a splash of milk, or try a new tea option when out and about. Aim to drink no more than 2-3 small glasses of wine (or the equivalent in your beverage of choice) per week. Make sure your meals are high enough in protein, healthy fats, and fiber to keep you fuller for longer. This will stabilize your blood sugar levels and help to prevent you from snacking later on.

If you do opt for a snack, aim to pair a source of protein, like cottage cheese, peanut butter, or Greek yoghurt, with a complex carb such as a slice of wholegrain sourdough bread, or a handful of oats. Avoid eating ‘naked carbs’ which spike your blood sugar and promote overeating.
Other strategies for cutting calories include:
● Eat a large salad before your meal to reduce your overall consumption
● If you like having sugary fizzy drinks, first switch to diet versions, and then ultimately aim for a glass of fizzy water with fresh lemon or lime
● Avoid fruit juices, and instead, squeeze a little fresh orange into a glass of water for a fruity boost
● Consider the balanced place concept – fill half your plate with non-starchy vegs such as spinach, red onions, and tomatoes, a quarter of the plate with protein such as a salmon fillet or chicken breast, and the final quarter with wholegrain carbs such as brown rice, or complex carbs such as sweet potato

Do weight loss injections work?

You might have recently read about weight loss injections such as Wegovy and Ozempic. Whilst it’s tempting to think that these can offer you the weight loss you desperately crave – what isn’t usually advertised is that they are also only a short-term fix.

Studies have shown that once people stop taking these injections (made from semaglutides – originally intended for diabetics) up to 75% will regain 2/3rds of the weight they lost, within a year. So, for many – the risk of severe side effects, the increased incidence of cancer, and the long-term ineffectiveness renders such interventions pretty pointless.

How can I safely lose weight?

The best approach is to be realistic, and patient and to adopt a detailed, holistic plan that will work for you on a long-term basis. Firstly, figure out how you will achieve your calorie deficit. Will you cut back on alcohol, sweet drinks, creamy coffees, or snacks? Then, make a clear idea of what you will replace these with – make sure you find enjoyable replacements that will work with your lifestyle.

It’s also important to structure your meals to meet your macronutrient requirements (via the balanced plate concept we discussed above). Focusing on fiber, hydration, and protein will help you to obtain the ‘fullness factor’ to prevent overeating and blood sugar dips.

As part of your sustainable weight loss plan, it’s also super important to consider your sleep and stress strategy. This is because poor sleep is linked to an increased desire for highly palatable foods. These high-fat, sugar, and calorie foods can make it pretty hard to stick to your calorie deficit. Instead, by prioritising quality rest and relaxation you can lower your stress hormones and promote good sleep. When you sleep well, you’re more likely to feel like being active and making good food choices – which can help you with your long-term weight loss goals.

References

Why Diets Don’t Work

Why diets don’t work

What do we mean by diets?

Why aren’t diets successful in the long term?

How does the body respond to extreme calorie restriction?

What does sustainable weight loss mean?

How to cut 500 calories a day?

Do weight loss injections work?

How can I safely lose weight?

Author Carl Liver

Why Diets Don’t Work

Why diets don’t work

What do we mean by diets?

Why aren’t diets successful in the long term?

How does the body respond to extreme calorie restriction?

What does sustainable weight loss mean?

How to cut 500 calories a day?

Do weight loss injections work?

How can I safely lose weight?

Author Carl Liver

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