Hi! I’m Elly Ling, and I’m a registered Nutritional Therapist.

I’ve teamed up with Weight Loss HQ by Treated to help you find the most helpful diets out there if you’re taking weight loss medication, and separate some fact from fiction when it comes to eating habits and exercise.

Today I’m going to talk about fad diets, how well they work, and whether you should be following any alongside your treatment.

Let’s dive in.

Okay, so this is a pretty famous one: the ketogenic diet (or ‘keto’, for short). If you’re not familiar, the keto diet basically involves cutting right back on carbs, so you only eat very little carbs or none at all. By doing this, you probably will lose weight, but it can come with problems and complications.

Carbohydrates are a really important energy source for our bodies and brain, so cutting them out can make it harder to exercise and focus on day to day tasks. If you follow the keto diet perfectly, (in theory) you shouldn’t feel a drop in energy because your metabolism will shift and your body will run off ketones.

But in practice, this is really hard to achieve, particularly on an on-going basis. And when you do have carbs at this point, you’ll come out of ketosis, and start to feel tired and lethargic quite a lot, so it’s not an easy diet to stick with long term.

The weight you might initially lose on the keto or low carb diet can be mostly water weight too, because cutting out carbs dramatically reduces glycogen in the body. For each gram of glycogen your body stores, it also stores around 3 grams of water. So when you start to eat carbs again, it might feel like you’re putting weight back on, because you’re building up glycogen stores again but also gaining water.

Going ‘keto’ can also make it harder to get the wide range of nutrients and minerals that you need. For example: just eating steak, butter, and chocolate would follow the keto diet rules, but it won’t do you much good. It also means you’ll cut back on some nutrient dense foods too, like beans and legumes, which are really good for gut health and digestion and packed with vitamins and minerals.

Next up, intermittent fasting.

This is when you don’t eat for long periods of time (say for 16 hours in the day), followed by periods of unrestricted eating (say for 8 hours in the day).

Most people eating this type of diet end up cutting down on their daily calories, and some research has shown it can be beneficial for energy levels and weight loss. But it can lead to disordered eating, and shift your focus away from eating healthily.

It’s also not really suitable for people on weight loss injections, as following this type of diet can overwhelm your digestive system and make you feel nauseous.

Lastly, let’s talk about liquid diets, or ‘juice cleanses’.

This is where you have no solid foods in your diet, with the primary aim of restricting the number of calories you consume. The good thing about it is that it can increase your fruit and veg intake, and keep you well-hydrated.

But there are a lot of issues with it.

Juicing fruit and veg removes the skin and pulp, which is where all the fibre is, and you need this for good gut health and digestion.

Smoothies made from lots of juiced fruits can be really high in sugar, so you might get energy crashes and spikes. And with a liquid diet you might get other side effects, like diarrhoea and constipation.

So it’s a hard diet to keep up, and it’s really not compatible with weight loss medication; there’s a good chance you’ll get nausea and not feel too great.

Bottom line? Fad diets might help you lose weight for a little while, but in the long-term, the negatives often outweigh the positives. It’s much better to make sensible, healthy changes to your diet that help you feel good about eating, and you’ll have the best chance of sticking to it for years to come.