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The weight loss dilemma: “Real” vs “diet” foods

Image of diet foods on table
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When trying to lose weight, it’s normal to find yourself drawn to foods in the supermarket labelled with the words “diet” or “low-calorie”.

It’s tempting to see these foods as a shortcut to weight loss and therefore the “healthy” option. But the truth is, many of these diet foods – while low in calories – will be ultra-processed, low in essential nutrients and packed with hidden unhealthy ingredients.

In short, the healthiest weight loss foods will always be those you prepare yourself with fresh ingredients.

What are “real” foods?

When we talk about “real” foods we’re generally talking about foods that haven’t been overly processed.

There are plenty of processed foods that are perfectly healthy, including frozen veg, tinned fish and wholemeal bread. In fact, sometimes the processing of an ingredient can make it healthier – a good example is semi-skimmed milk, which has been pasteurised to make it safe to drink, and had some fat removed.

In general, though, food is more likely to be healthy if it hasn’t been ultra-processed i.e. prepared in a way that removes nutritional benefit or adds too much salt, sugar and fat.

With that in mind, “real” foods to base your diet around are:

  • Fresh or frozen fruits and vegetables
  • Fresh, dried or canned beans, lentils and peas
  • Wholegrain cereals like wholemeal bread, brown pasta and brown rice
  • Eggs
  • Unsmoked and unprocessed fish and meat
  • Low-fat milk, yoghurt and cheese

What are “diet” foods?

Diet foods are those in the supermarket that are marketed towards people trying to lose weight. Usually they’ll be labelled with the words “diet”, “low-calorie” or “calorie-controlled”.

Sometimes these foods might be tied to a specific kind of fad diet i.e. one that is very high in fat but low in carbohydrates. They may also be from a specific brand associated with weight loss.

There are also diet foods that aren’t labelled in such a direct way, but are still designed for people conscious about their health and weight. These foods include fat-free yoghurts, sugar-free fizzy drinks and savoury snacks pitched as “healthy” alternatives e.g. vegetable crisps.

Within this category you’ll find plenty of healthy foods, but you just have to be careful to read the nutritional information before you buy them.

A fat-free yoghurt might be packed with sugar, while a savoury snack might be low in calories but still high in salt. Something with a very high fat content may still be high in fat even if it’s labelled as “light” e.g. mayonnaise.

Understanding food and how to eat healthily

There are a few rules you can follow when you’re trying to eat healthily and lose weight. According to the NHS Eatwell Guide, we should all aim to eat the following in a day:

  • At least five portions of varied fruits and vegetables
  • Plenty of high-fibre and wholegrain starchy foods
  • A small amount of low-fat dairy or a dairy alternative
  • Healthy protein from pulses, fish, eggs and lean meat
  • Plenty of fluids

When shopping for healthy foods, be careful with products that seem to be geared towards weight loss, making sure you check the following:

  • Sugar content
  • Salt contact
  • Saturated fat content

Lastly, wherever possible, try to prepare and cook your own food at home. Going out for dinner or having a ready meal or takeaway is OK as a treat every now and then, but it’s much easier to eat well when you cook at home!


Many eating plans put emphasis on cutting back on carbs, but they’re an essential part of our diet as they give us energy and nutrients, and make us feel full and satisfied. The key is to make sure you’re eating the right kinds of carbohydrates.

Rather than relying on chips, white bread and white pasta, aim to eat high-fibre and starchy vegetables and wholegrain cereals, such as:

  • Potatoes with the skins on
  • Wholemeal bread
  • Brown rice
  • Brown pasta
  • Whole porridge oats

In total, healthy starchy foods like this should make up a third of your plate.


Most of us could do with eating more fibre – around 30g each day. It helps us stay full, prevents constipation, and lowers our risk of heart disease, stroke, type 2 diabetes and bowel cancer.

Fibre is found in fruits, vegetables, potatoes with the skin on, wholegrain cereals, pulses and nuts.


There are plenty of healthy foods rich in protein, including:

  • Beans, peas and lentils
  • Nuts and nut butters
  • Eggs
  • Fish
  • Lean poultry e.g. skinless chicken breast
  • Low-fat dairy

You can have red meat, but in smaller quantities (e.g. once a week). Processed meat like bacon, ham and sausages should also be eaten in much smaller quantities.

Though many eating plans but emphasis on getting lots of protein, the average person only needs about 0.75g per kilo of their body weight. This equates, on average, to 45g for women and 55g for men – or roughly two palm-sized portions each day.

Saturated fats

Saturated fats are those that raise your cholesterol and increase your risk of heart disease. They’re found in lots of snack foods, junk foods and processed foods, including:

  • Cakes and biscuits
  • Sausages and bacon
  • Fatty meats
  • Cheese
  • Cured meats
  • Pastries
  • Butter
  • Cream and ice cream
  • Chocolate

According to the NHS, men should aim to eat no more than 30g of saturated fats each day, and women no more than 20g.

Unsaturated fats

Mono-unsaturated fats and poly-unsaturated fats are healthier types of fat. These are found in:

  • Olive oil and rapeseed oil
  • Avocadoes
  • Almonds, peanuts and Brazil nuts
  • Oily fish

These foods are good sources of healthy fats, but it’s still important not to have too much of them.

Minerals and vitamins

Our bodies need a variety of nutrients each day, including vitamin C, vitamin D, vitamin B12 and calcium. The NHS recommendation is that you should be able to get everything you need by eating the kind of healthy, balanced diet set out in the Eatwell Guide.

One notable exception is vitamin D, which our bodies mostly generate through sun exposure. During the autumn and winter, when sunlight in the UK is too weak for our bodies to do this, it’s a good idea to take a vitamin D supplement.

Losing and gaining weight safely

When it comes to healthy weight management, the best place to start is with a trip to your GP. They’ll be able to give plenty of recommendations about how to lose or gain weight safely and whether you need help from a dietitian.

In the meantime, check out this page on the NHS website.

Weight loss service