5-2 Diet Spicy Tomato and Lentil Soup

5-2 Diet Recipe – Spicy Tomato and Lentil Soup

Whether you are trying to follow the 5:2 diet or following a more conventional low calorie diet, soups are a wonderful thing and this tomato soup, spiced up with chilli or paprika (or both) and thickened with healthy lentils is no exception.  Warming, filling and healthy – and very easy and cheap to make, the tomatoes give a rich flavour (they are full of umami) while the lentils are high in protein and fibre (50g of raw lentils have about six times the level of fibre and protein as  100g of potato, a common way to thicken this soup, but bulk up to about the same volume).  So if you are following a diet and think soup can’t be filling, try my tomato and lentil soup!

Looking back I guess I’ve done something like the 5:2 diet in the past when I used to have ‘soup days’ once or twice a week if I wanted to lose weight.  You can make up soups that are extremely low in calories and very comforting.

5-2 diet spicy lentil and tomato soup

The main thing to remember when following the 5:2 diet plan on fasting days  is that you need to avoid cream based soups – because once you start adding cream, the calories go up really quickly.  And, except as a garnish or stirred through at the end, you can’t add the low fat types of cream or yoghurt and cook with them, because they will split.

This Spicy Tomato and Lentil  soup is a store-cupboard recipe.  Most of the ingredients are things you should have in your cupboard already – so it’s perfect for one of those days when you planned to shop and then it started to pour with rain, or you got too busy.  The lentils add body to the soup but are also a great nutritional addition because they are high in protein and fibre (although the red ones that I use for cosmetic reasons here are not as high fibre as the posher green puy lentils).  50 grams of dried red lentils is enough for four portions of this soup – adding about 150 calories in total.

Spicy Tomato and Lentil Soup

Serves 4
Prep time 10 minutes
Cook time 30 minutes
Total time 40 minutes
Dietary Vegetarian
Meal type Soup
Misc Freezable, Pre-preparable, Serve Hot


  • 1 tin Chopped tomatoes
  • 1 Medium Onion (Finely chopped)
  • 1/2 Red Chilli (De-seeded - or dried chilli flakes to taste)
  • 50g Dried red lentils
  • 1 Carrot (Peeled and chopped)
  • 1l Chicken or vegetable stock (I use Knorr touch of taste chicken stock made up with 1.5 teaspoons)
  • 1 teaspoon Sunflower oil


  • 1 heaped teaspoon Low fat yoghurt or creme fraiche
  • 1 stick Celery (Chopped)


Step 1 Put the oil in a large heavy bottomed pan on a medium heat and soften the onion, carrot, celery if using and chilli for 8-10 minutes
Step 2 Pour in the stock and tomatoes and add the lentils
Step 3 Cook for at least 25 minutes on the hob till the lentils are soft and the mixture has reduced down a little. Check and adjust seasoning, adding salt and pepper as required. If you do not want the soup to get any hotter, remover the chilli at this stage.
Step 4 Blitz the soup with a wand mixer till nearly smooth
Step 5 Serve with a dollop of low fat yoghurt or creme fraiche, or if you prefer with a scattering of crunchy croutons.

80 Calories per portion (without the creme fraiche or yoghurt)

This recipe has been a winter staple of mine for years.  I do experiment with the spices – you can add cumin or cardamom if you like them, and coriander is a nice garnish if you have any (I don’t right now!).  I’ve made a spicey but not hot version using sweet paprika too.   I have never really worried too much about the calorie content but one of the effects of doing the 5:2 diet is that you do think quite hard about what you are eating in terms of nutrition and calories.  I’m also finding that the 5:2 diet is reducing my appetite on non-fasting days – I’m not eating very differently but I AM eating less, and I’m definitely losing weight and feeling better!

Looking for some 5:2 diet alternatives? Here are a few…

Tomato Soup with Roasted Garlic for 5:2 – this is a summer/autumn soup, best made when tomatoes are fresh!

5:2 Diet Chilli Beef – the chilli is a great way to raise your metabolic rate and burn even more calories

5:2 Diet Celery and Spinach soup – a simple, comforting low calorie soup

5:2 Diet and Celeriac – Watercress and Celeriac Soup Celeriac – a secret ingredient for the 5:2 diet

Comforting 5:2 Diet Smoked Haddock Rarebit – haddock is very low in calories, so you can make a smoked haddock rarebit, use low calorie cheese for under 400 calories

Exotic lime and chilli seared scallops for the 5:2 Diet – treat yourself to a low calorie feast!

Livorno Fish Stew for the 5:2 Diet – more fish – it’s one of the easiest ways to keep to a low calorie diet!

Tarragon Chicken Parcels for 5:2 Diet simple, tasty and something you can serve to the whole family – 5:2 diet friendly

Galician Hake the Low Calorie 5:2 diet way!  A lovely warming dish that I could eat whether or not on a diet

Fish and chips for 5:2 Diet Fish and Chips low calorie low fat recipe for the 5:2 diet

Lemon and Coriander chicken for the 5:2 diet low fat, Low calorie chicken Curry recipe for the 5:2 diet

Tuna, Courgette and Aubergine Sicilian styleSicilian Tuna with Aubergine and Mint for the 5:2 Diet – low calorie, low fat and lots of flavour


Or if you would like to hear about the 5:2 Diet from the original BBC programme on Horizon check out the link

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  1. Rebecca says

    I’m definitely trying this recipe this weekend – love anything with tomatoes and soup is always welcome during winter. Thanks for sharing!

  2. kathleen hooper says

    I’ve just tried this soup: it was perfect for a cold winter’s lunch. Next time I’ll make more and have some spare for taking to work

  3. Michael says

    Hi have been using this soup for lunch on my 5-2 fast days for 7 weeks now, and not bored of it.
    I do add more chilli and keep the seeds in as like it hot :)
    So thankyou very much for this soup.

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