For those trying to lose weight, the notion that it can be done quickly and easily is an incredibly appealing one.

As a result, those ‘shortcut’ methods which claim to enable practitioners to get fast results are a popular endeavour.

However, it’s often the case that these methods aren’t quite as straightforward as they seem; and even if they do work, they only do so in the short term.

Obviously weight loss isn’t an exact science. There are multiple schools of thought on the subject from experts all over the world. Many medical theories will enjoy spikes and dips in credibility: one expert will champion an idea, and then another will disagree with it, and the process continues.

Inevitably the result of all this is that the lay person will read and hear different theories in the media, and be led to believe different things.

However, an important fact to consider about weight loss is that one size never fits all. Just because a weight loss technique is successful in one instance, doesn’t mean it will be successful in everyone’s.

With that in mind, we thought it might be useful to examine some weight loss-related theories which have been popular in recent years, and why they may not be quite as straightforward as you might think:

  1. Theory 1: Avoiding carbs
  2. Theory 2: Low fat foods
  3. Theory 3: Banning treats
  4. Theory 4: Late night eating
  5. Theory 5: Skipping breakfast
  6. Theory 6: Vigorous exercise
  7. Theory 7: Water burns calories
  8. Theory 8: My friend's diet

Theory 1: Those trying to lose weight should completely avoid carbs

This particular theory came to prevalence with the rise in popularity of the Atkins diet, which famously involved avoiding carbs in favour of foods high in protein, such as meat, eggs and cheese. It originally provided virtually no limits on fat consumption (but has since been adjusted).

There have been several studies to determine the efficacy of such a dietary approach. One notable study in the New England Journal noted that, while a low-carb diet produced beneficial results in terms of weight loss in the short term (3-6 months), in the long term (at 12 months), these benefits were not that different to those undertaking a more traditional low-fat diet; which suggests that those on low-carb diets are more likely to regain weight after an initial period of loss.

Carbohydrates contain less than half the calories of fat per gram, and are a vital source of energy and nutrition, which should make up around a third of food consumed as part of a healthy diet. The fibre in these foods can also help us to feel full, reducing the chances of us raiding the fridge before the next meal.

Most of the calories from the starchy foods we eat in the carbohydrate family come from the things we add to them, be it cheese in a sandwich, a shop bought pasta sauce with added sugar, or potatoes fried in oil.

To help lose weight and then maintain this loss, high fibre carbs such as whole grain breads, brown rice or pasta, and baked potatoes with the skin left on, are recommended. It’s also important to be mindful of what is being added to them, and consider healthier alternatives.

Theory 2: Eating low fat versions of food will make you lose weight

Not necessarily. Substituting our favourite food items with low fat versions seems like an easy shortcut to a healthier diet. But in actuality, the benefits are minimal.

It’s an unfortunate fact that fat helps to make food taste better. If you take fat away, you’re affecting the taste. The way many food manufacturers maintain a similar taste to the food is by increasing the amount of sugar in it, thereby negating the positive effects of eating the lower fat version. Another trick is to replace it with more salt, which most people in the UK already eat too much of.

Reduced fat foods can be marketed as such if they contain at least 30% less fat than the full fat version. So for example, a product very high in fat such as cheese will still be high in fat in its reduced fat variant; this doesn’t necessarily make it a ‘low fat’ choice.

The alternative option is simple portion control. This means buying food with normal levels of fat, and all of the taste, but simply eating less of it.

If you do decide on buying low fat versions of food, take a look at the nutritional information first, and check that the reduced fat content isn’t compensated for with added sugar.

Theory 3: Cutting out all treats is the key to weight loss

Too many ‘treat’ foods (namely those high in sugar or saturated fat) can obviously increase a person’s calorie intake and make it harder for them to lose weight. But does that mean cutting them out completely is the key to sustained weight loss?

A balanced diet is exactly that; there is nothing wrong with an occasional indulgence as long as they are consumed in moderation.

As such a diet won’t be harmed by the occasional treat; if anything it will help in the long run, as it will stop someone from feeling too deprived of their favourite foods and prevent them succumbing to temptation in more drastic fashion further down the line.

When someone reduces their calorie intake, the levels of a hormone called leptin, which regulates hunger, diminish, making them crave more food. Eating the odd treat will raise leptin levels, stop feelings of hunger and prevent the body from conserving fat.

Theory 4: Eating late at night leads to weight gain

The idea that eating after 8pm in the evening cause significant weight gain has been debunked or deemed inconclusive by several studies. A calorie has the same value regardless of when it is consumed.

The theory likely has more to do with what people tend to eat late at night. People will be less inclined to prepare their own food after a certain time and instead opt for a convenient snack or takeaway. Crisps, chocolate, ice cream and takeaway foods all tend to be high in fat or sugar, or both.

If you’re more likely to eat this sort of food at night, you may want to think about changing your eating habits to ensure you eat a balanced diet during the day, so you aren’t as likely to crave them before bed.

Theory 5: Skipping breakfast is a good way to lose weight

Simply put, people who have a healthy breakfast find it easier to manage their weight.

In addition to hunger pangs, missing breakfast or other meals will send blood sugar into free fall. This can lead to feelings of tiredness and irritability, and the body’s metabolism will actually slow down as it tries to conserve energy.

To make matters worse, when those who skip breakfast do eventually eat, they are more likely to go for food dense in sugar and fat to compensate for the meals they have missed. Furthermore, as their metabolism will still be in ‘conservation mode’, they will have to work harder to shift the calories.

Eating regular meals throughout the day, and making these smaller and healthier, can help those concerned about their weight. It will be more effective in the long run and make someone less susceptible to mood swings.

Theory 6: Vigorous exercise is the only way to lose weight

There are of course many health benefits associated with exercise. However losing weight through exercise alone is extremely hard work.

The NHS recommends 150 minutes of moderate physical activity per week for a normal adult, but more is required for weight loss. A study from the Royal Society of Public Health found that it takes 22 minutes of running to burn off the calories in the average chocolate bar, and 43 minutes to run off a quarter of a large pizza.

To lose weight someone will need to burn off more calories than they consume, and the most feasible way to do so is through a combination of both physical activity and the right diet.

Exercising for weight loss doesn’t always need to involve pumping iron or hitting the running machines. Brisk walks, dancing and mowing the lawn are just some of the activities that can be beneficial.

Of course vigorous exercise will burn off more calories than moderate exercise. But physical activity needs to be undertaken regularly; and for someone new to exercise, it’s more important to get into the habit and keep it going. This might not always be feasible by jumping into vigorous exercise headfirst.

Theory 7: Drinking water makes you burn lots of calories

While studies have shown drinking water can help to burn more calories, the effect is minimal.

However, keeping hydrated is vital for health, and drinking water rather than sugary soft drinks is an easy way to avoid empty calories.

It’s also possible to mistake thirst for hunger, and drinking water can help you to feel full. So, the next time you feel like reaching for a snack, a glass or water may be able to satisfy your craving.

Theory 8: If a diet has worked for one of my friends it will work for me

We all have different body shapes, metabolic rates and underlying health conditions. If a weight loss programme works for one person, it may well not work for someone else. Some people have more active lifestyles or physically demanding jobs than others, and age and genetics also play a part.

If you have a problem with your weight, or are thinking of embarking on a diet, speak to your doctor. They will be able to discuss with you the factors potentially affecting your weight and advise you on a plan of action suited to your needs.

If your weight has become a risk to your health, your doctor may prescribe weight loss medication to help manage your weight, alongside an exercise and diet programme.

Page last reviewed:  24/12/2020