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Food, Money, Save It, Slimming

SlimFast 321 | how to do the SlimFast diet on a budget

The image shows some discounted SlimFast 321 products alongside a receipt. The image has a green border.

The weight loss industry is worth billions and if you decide to follow a particular plan, then the chances are, it will cost you money. I decided to try the SlimFast 321 regime and after an eight-week stint, I can confidently say that this is a diet you can follow if you’re on a budget. You’ve just got to be savvy shopper that keeps my thrifty tips in mind when sourcing the items needed for your new eating regime.   

What is SlimFast 321?

SlimFast has been around since the 1970’s, but SlimFast 321 is the plan that the company is currently promoting. The concept is pretty simple; you have three 100 calorie snacks each day, two shakes or meal replacement bars and then you have one 600-calorie meal. So essentially, it’s a calorie controlled diet, but the SlimFast products make it easy to stay on track.

How does SlimFast 321 work?

With this diet plan, you essentially eat three snacks per day, two shakes and one meal. The shakes you have have been formulated especially by SlimFast and they’re available on the highstreet.

SlimFast has a range of snacks and meal-replacement bars that you can buy too. But it is possible to make your own 500-calorie meal and to source your own 100-calorie snacks. There are heaps of healthy recipes available online and lots of snacks under 100 calories that you can buy. No foods are off the table, they just need to be within the calorie goal. 

The SlimFast diet essentially puts you into a calorie deficit, which is why you lose weight. 

Issues with my weight

I’ve been overweight for most of my life. And, spoiler alert, I am still overweight. This has always been a personal struggle for me. I’ve done Slimming World to lose weight, but after piling on weight during lockdown, I decided to take control of my eating and try something new.

The SlimFast 321 plan appealed to me because it meant that I only had to think about one meal each day. I felt that this type of system would work with my lifestyle, because I find that I often skip meals due to not knowing what to eat and get ravaging hungry. My hope was that having something set to consume for my breakfast and my lunch would help with that. I spoke to my doctor before embarking on the SlimFast plan and she told me that she fully supported my decision. She explained that it wasn’t something anybody did forever, but it was a tool that she was happy for me to use in the short-medium term. 

Trying this weight loss plan

I did the SlimFast 321 plan for eight weeks now and I’ve lost 14lb in total. In my first week I lost 7.5lb, which is unheard of when it comes to my dieting history. I was really pleased with those results and I’m not currently on the Slimfast 321 plan, I do still enjoy the occasional shake.

Being the thrifty queen that I am, I wanted to ensure that SlimFast 321 was as affordable as possible. Here are my tips, if you fancy trying the SlimFast plan on a budget:


1) Look out for offers

Products associated with the SlimFast plan are stocked by chemists and supermarkets, which means that somebody is usually running an offer. I have seen them range from £2 off a SlimFast shake product, to buy-one-get-one-free promotions. If you join one of the SlimFast Facebook support groups, you can always ask if anybody knows of any promotions that are running before doing your shop.

2) Check the discount shelf

I thought I’d won the SlimFast lottery when, two days into my new regime, I stumbled across a SlimFast 321 7-day bundle for £5 instead of £30. Alongside this, I spied three ready-to drink shakes for 50p each (instead of the usual £2.10 each). I actually bought my haul using my Boots Advantage Card points, so it was technically free. That makes it an even better bargain!

But finding this type of discount on SlimFast products isn’t particularly rare, so keep your eyes peeled. When the products only have a month or two left before the best by date, chemists heavily reduce these items and pop them on the final clearance shelf. So if you’re following SlimFast 123, or you’re interested in it, it’s probably worth checking Boots and Superdrug when you’re passing on the off chance. 

3) Seek out alternative snacks

SlimFast has a small range of 100-calorie snacks and I think that the sour cream and chive flavoured pretzels are divine, so I always try to ensure that I have some of them in. However, you’ll find much cheaper 100-calorie snack alternatives that are easy to source. You could eat a piece of fruit, a supermarket-branded packet of crisps, or a Slimming World HiFi Bar as an alternative. By doing this, you’ll save some serious cash. I also think that you quickly learn which snacks are around 100 calories, so before long you’ll have a great go-to list. 

4) Make shakes if you’re at home

The beauty of SlimFast 321 is that you can eat easily on the go. However, if you’re at home, then it’s much more cost efficient to make your own shake up. For that reason, I use the SlimFast powder to create shakes when I’m at home and I save the pre-made ones for when I’m out and about.  

Full disclosure though, I use a NutriBullet and ice when I’m making my shakes up. I find that they’re much more palatable that way. 

5) Try a variety pack (which includes snacks and meal replacement bars)

I’m personally yet to try a SlimFast shake that I find undrinkable, but I certainly like some more than others. If you’re on a budget, then you might not want to invest in a lot of different shakes, so I’d advise you to purchase a variety pack at the start of your journey. This will help you to figure out which shake flavours to invest in.

6) Check the size of the tub

The tubs of SlimFast shake come in various sizes. You can get a 10, 12, 16 or 50 meal tub. Make sure you check what you’re paying per 100g, because the smallest tub may not be the most economical.

7) Approved Foods and Home Bargains

You can usually snap up SlimFast products on Approved Foods for cheap. I have seen 7-day bundles listed on there for 50% less than usual. Home Bargains also sells SlimFast products. If there isn’t a good offer running elsewhere, then Home Bargains seems to be the cheapest place to purchase SlimFast 321 items on the highstreet. 

The image is of some discounted SlimFast 321 products. Over the image, the text reads: 'hacks: how to do SlimFast 321 on a budget'.

Is it worth trying this diet plan?

When it comes to diets, I’d say that the SlimFast plan was an easy one to follow.  The rules are quite simple and if you stick to the SlimFast plan, you will see results quite quickly. You don’t need to worry about nutrition either, as the shakes are balanced and you can read information about that on the side of each product. 

By shopping around and being savvy, I also think it’s possible to follow the SlimFast diet on a budget. Even if you don’t manage to find a clearance shelf SlimFast haul, you could buy a 10-shake tub from Home Bargains that you just have to add skimmed milk to, for £4.99. That means that each SlimFast shake (meal) would cost less than £1 to make. I also think that it’s easy to source affordable food that only contains 100 calories. 

If you decide to try the SlimFast 321 weight loss plan, then I hope that my tips help you to do it affordably. If you’re determined to lose weight, you want to make some lifestyle changes and you fancy making some money doing so, then check out my DietBet review



Editor’s note: This post was originally published in January 2021 and has been completely revamped for accuracy and comprehensiveness.