7 Foods You Should Never Eat to Lose Weight: Your Complete Guide

Are you struggling to lose weight despite trying every diet under the sun? The problem might not be what you’re eating—it’s what you’re still eating. Whilst countless fad diets promise rapid results by eliminating entire food groups, the truth is simpler: there are seven specific foods sabotaging your weight loss efforts, and removing them from your diet can make all the difference.

This isn’t about deprivation or following the latest trend. These are permanent, sustainable swaps backed by nutritional science and NHS guidelines. By cutting these seven foods from your diet—one at a time—you’ll adjust to your new lifestyle easily whilst watching the weight come off and stay off.

In this article, we’ll reveal the 7 foods destroying your weight loss goals, explain exactly why they’re harmful, and provide practical UK alternatives you can start using today.

The Top 7 Foods You Should Never Eat

Now let’s explore each of these foods in detail, examining why they’re problematic for weight loss and, most importantly, what you can eat instead. For each food, you’ll find practical strategies to eliminate it from your diet without feeling deprived.

1. Fizzy Drinks (Soft Drinks) – Empty Calories in Every Sip

Fizzy drinks are genuinely one of the worst things you can consume for weight loss, yet they’re also one of the hardest habits to break. Whether you call it soda, pop, or soft drinks, these beverages are essentially sugar dissolved in carbonated water with a cocktail of chemicals to create “cola” or “orange” flavour.

The Nutritional Reality

A standard 330ml can of fizzy drink contains approximately 139 calories and 39 grams of sugar—that’s nine teaspoons, which exceeds half your daily recommended intake according to NHS guidelines. The sugar content alone makes fizzy drinks incredibly high in calories, whilst being virtually devoid of any nutritional value.

For anyone watching their sugar intake or trying to lose weight, these drinks are particularly dangerous because your body doesn’t register liquid calories the same way it does solid food, meaning you won’t feel full despite consuming significant calories.

Why They’re Everywhere

The challenge with fizzy drinks isn’t just the health impact—it’s the availability. They’re sold at every restaurant, petrol station, cinema, and sporting event across the UK. Often, they’re cheaper than bottled water, making them an easy default choice. This ubiquity makes them one of the foods you should never eat (or rather, drink) if you’re serious about weight loss.

Your Practical Swap Strategy

Breaking the fizzy drink habit requires a gradual approach:

• Week 1: Replace one fizzy drink per day with sparkling water. Add fresh lemon, lime, or cucumber for flavour.
• Week 2: Replace two fizzy drinks daily. Try diluted fruit juice (one part juice to three parts water) for a touch of sweetness.
• Week 3: Keep fizzy drinks for weekends only. Experiment with unsweetened iced tea or coconut water.
• Week 4: Reserve fizzy drinks for special occasions. Your taste buds will have adjusted, and you’ll find them overly sweet.

Alternatives That Actually Work

• Sparkling water with fresh mint and berries
• Diluted apple or cranberry juice
• Kombucha (naturally fermented, low sugar)
• Homemade fruit-infused water
• Unsweetened herbal iced tea

Pro Tip 

Always bring your own water bottle. If you don’t have fizzy drinks at home, you’re far less likely to drink them. When dining out, order sparkling water with fresh lemon—it feels special without the sugar hit.

2. Chips (French Fries) – The Hidden Calorie Bomb

Chips—or French fries if you’re watching American telly—are one of the most dangerous foods for anyone trying to lose weight. The primary issue isn’t just that they’re fried; it’s that portion control becomes virtually impossible, and you can never accurately judge their calorie content.

The Portion Control Problem

Here’s something shocking: a recent survey found that many UK fast-food restaurants give customers 30% more chips than the portion size listed on their menu. Restaurants do this because chips are cheap to produce, so giving generous portions seems like good value. However, this “generosity” sabotages your diet completely.

Why Calorie Counts Are Misleading

A change in the type of oil used for frying, cutting the chips slightly thicker or thinner, or how long they’re cooked can dramatically affect the calorie content. The same “medium portion” of chips can range from 312 calories to over 500 calories, depending on these variables. When you’re trying to track your intake, this unpredictability makes chips one of the foods to never eat regularly.

According to research published in nutrition journals, deep-fried potatoes not only carry excessive calories but also contain acrylamide—a compound formed during high-temperature cooking that’s been linked to various health concerns.

Restaurant Chips Are the Worst Offenders

Low-end restaurants and fast-food chains typically use the lowest quality oils and often reuse them multiple times, adding even more unhealthy fats to your meal. These establishments also tend to add extra salt to mask the taste of overused oil, creating a triple threat: excess calories, unhealthy fats, and high sodium.

Making the Switch

Fortunately, most people only eat chips when dining out, which makes this one of the easier foods you should never eat to eliminate. The key is having a plan before you order.

Healthier Alternatives

• Oven-baked sweet potato wedges (half the calories)
• Steamed seasonal vegetables with herbs
• Side salad with olive oil dressing
• New potatoes with fresh mint
• Jacket potato with Greek yoghurt

Restaurant Strategy

When ordering, immediately ask for a side salad or vegetables instead of chips. Adding a small amount of salt will give you the sodium satisfaction without consuming hundreds of extra calories. If you’re at a pub, opt for the seasonal vegetable medley—most UK pubs now offer excellent alternatives.

3. Packaged Biscuits – The Preservative Problem

Have you ever wondered why biscuits you bake at home go stale within a week, yet packaged biscuits from the supermarket taste fine years after production? The answer lies in what makes packaged biscuits one of the foods you should never eat: chemical preservatives, excess sugar, and unhealthy fats.

The Shelf-Life Secret

Prepackaged biscuits and other commercial baked goods are laden with chemical preservatives to extend their shelf life. To keep them tasting fresh, manufacturers significantly increase the fat content. Then, to mask the unpleasant taste of preservatives, they add substantially more sugar than you’d find in homemade or fresh bakery biscuits.

The Hidden Calorie Cost

Whilst the preservatives themselves aren’t necessarily harmful in small quantities, they can cause digestive discomfort in many people. More importantly, the combination of extra fat and sugar means packaged biscuits contain significantly more calories than their homemade counterparts. A typical packaged digestive biscuit contains around 80-85 calories, whilst chocolate-covered varieties can exceed 150 calories per biscuit.

According to NHS nutritional guidelines, the recommended daily sugar intake is no more than 30g for adults. Just three packaged chocolate biscuits can contain 15-20g of sugar—that’s over half your daily allowance in a small snack.

The Mindless Eating Trap

Because packaged biscuits are designed for long shelf life, they’re always available in your cupboard. This constant availability leads to mindless snacking—grabbing a few biscuits with your tea without considering the caloric impact. Before you realise it, you’ve consumed 400-500 calories without feeling satisfied.

Your Biscuit Strategy

You don’t need to eliminate biscuits entirely from your life—they’re part of British culture, after all. Instead, change how you consume them.

• Make Them at Home: Baking your own biscuits means you control the ingredients. You’ll naturally make them less frequently, turning them into a special treat rather than a daily habit. A batch of homemade shortbread uses real butter, flour, and sugar—nothing you can’t pronounce—and tastes infinitely better.
• Buy Fresh from Local Bakeries: If baking isn’t your forte, visit a local bakery. Yes, it costs slightly more than supermarket packets, but you’ll buy fewer biscuits and enjoy them more. The higher price point also makes you more mindful about consumption.

Alternatives When You Need Something Sweet

• Fresh fruit with a small amount of dark chocolate
• Greek yoghurt with honey and crushed nuts
• Homemade oat bars (control the sugar content)
• Rice cakes with almond butter
• Fresh bakery scones (occasionally)

Pro Tip

If you must keep packaged biscuits at home, buy them in small quantities and store them out of sight. Research shows that foods kept in visible locations are consumed 70% more frequently than those stored in cupboards.

4. Chocolate Bars – Sugar-Laden Preservative Bombs

Much like packaged biscuits, commercial chocolate bars are another category of foods you should never eat regularly. Whilst an occasional treat won’t derail your diet, making them a daily habit will absolutely sabotage your weight loss efforts.

The Preservation Challenge

Chocolate bars face a unique manufacturing challenge: keeping “wet” ingredients like caramel and peanut butter from making “dry” ingredients like biscuit pieces and peanuts soggy. The solution? More chemical preservatives. These preservatives can extend shelf life to several years, but they require substantial amounts of added sugar to mask their taste.

The Peanut Butter Deception

Many people assume that chocolate bars containing peanuts or peanut butter offer some nutritional value—protein from the nuts, perhaps. However, the peanut butter used in commercial chocolate bars bears little resemblance to what you’d find in the supermarket’s nut butter aisle. It contains significantly more sugar and is processed to be much drier, which helps preserve the bar’s texture but eliminates much of the nutritional benefit.

A standard chocolate bar in the UK contains between 200 and 300 calories, with some larger bars exceeding 400 calories. That’s equivalent to a small meal, yet provides virtually no nutritional value—just sugar, unhealthy fats, and empty calories.

The Vending Machine Trap

One of the biggest problems with chocolate bars is their convenience. They’re available in every vending machine, petrol station, and supermarket checkout. When you’re tired, stressed, or simply bored, reaching for a chocolate bar becomes automatic. This mindless consumption—grabbing one from the office vending machine at 3 pm or buying one with your petrol—adds hundreds of unnecessary calories to your daily intake.

Breaking the Chocolate Bar Habit

The key to eliminating chocolate bars from your diet isn’t willpower—it’s preparation and substitution.

Healthier Chocolate Alternatives

• Dark chocolate (70% cocoa or higher)—Rich flavour means you’ll eat less
• Homemade chocolate treats using cocoa powder and honey
• Chocolate-covered strawberries (make them yourself)
• A small square of quality chocolate with afternoon tea
• Cocoa nibs mixed into Greek yoghurt

The Homemade Advantage

If you truly love chocolate bars, learn to make simplified versions at home. Whilst the process is time-consuming, this ensures you only make them for special occasions rather than consuming them mindlessly three times a week. Homemade versions taste better, contain recognisable ingredients, and help you appreciate them as the occasional treats they should be.

Practical Strategy

Remove chocolate bars from your regular shopping list. If they’re not in your house, you can’t eat them mindlessly whilst watching television. When you do fancy chocolate, walk to a local shop and buy a single piece of quality dark chocolate rather than a multipack from the supermarket.

5. Bacon – The 45% Fat Breakfast Mistake

Bacon has experienced a surge in popularity over recent years, appearing in everything from breakfast rolls to burger toppings. However, it remains one of the foods to never eat if you’re serious about weight loss and overall health.

The Fat Content Reality

Traditional pork bacon is typically over 45% fat. Yes, you read that correctly—nearly half of what you’re eating is pure fat. Some lower-quality bacon sold in budget supermarkets contains over 70% fat. When you factor in that many restaurants add extra oil or butter while cooking, you’re consuming processed meat that’s absolutely laden with fat, calories, and sodium.

According to NHS guidelines, processed meats like bacon should be limited to no more than 70g per day, yet a typical “full English breakfast” contains far more than this amount.

The Sodium Problem

Beyond the fat content, bacon is one of the saltiest meats available to consumers in the UK. A 100g serving of bacon contains approximately 1,400-2,000mg of sodium—that’s nearly the entire recommended daily intake of 2,300mg. Excessive sodium intake contributes to high blood pressure, water retention, and that bloated feeling that makes you think you’ve gained weight overnight.

Restaurant Bacon Is Worse

When you order bacon at a café or restaurant, you’re almost always getting the lowest quality meat available. Budget establishments purchase bacon with the highest fat content because it’s cheaper, and they often fry it in additional oil rather than grilling it. This cooking method adds even more unnecessary fat to an already problematic food.

The calorie count for 100g of cooked bacon ranges from 400 to 541 calories, with most of those calories coming from fat rather than protein. Compare this to grilled chicken breast at 165 calories per 100g, and you’ll see why bacon tops the list of foods you should never eat regularly.

Making the Transition

For meat lovers, giving up bacon can feel impossible. The good news? You don’t have to eliminate the experience of having something savoury and satisfying with your breakfast—you just need better alternatives.

Bacon Alternatives

• Turkey bacon (60% less fat than pork bacon)
• Lean back bacon with visible fat removed
• Vegetarian bacon made from tofu or tempeh
• Smoked mackerel (healthy omega-3 fats)

Cooking Method Matters

If you occasionally eat bacon, always grill it rather than frying. Place it on a wire rack so excess fat drips away during cooking. Remove any visible fat before eating. These simple changes can reduce the fat content by 30-40%.

Restaurant Strategy

When ordering a full breakfast, ask for grilled tomatoes, mushrooms, and an extra egg instead of bacon. Most establishments will accommodate this request, and you’ll still have a satisfying, protein-rich breakfast without the excessive fat and sodium.

6. White Bread – The Nutrition-Stripped Staple

White bread is a staple in most UK households, yet it’s one of the most problematic foods you should never eat when trying to lose weight. The issue isn’t bread itself—it’s what happens during the manufacturing process that strips away virtually everything beneficial.

The Bleaching Process Problem

White bread begins with wheat, which naturally contains fibre, vitamins, minerals, and protein. However, to create that soft, white texture consumers expect, manufacturers use bleached, highly processed flour. This process strips away the wheat germ and bran—the parts containing all the nutrients and fibre—leaving behind only the starchy endosperm.

To compensate for the lack of natural flavour and to help with the rising process, manufacturers add extra sugar or syrup. The result is a loaf of bread that’s high in calories, low in nutrients, and contains virtually no fibre.

Why You’re Still Hungry

Here’s the real problem with white bread: even though you’re eating a normal-sized sandwich, you won’t feel satisfied afterwards. According to research on satiety and nutrition, fibre is crucial for feeling full. White bread contains only about 2-3g of fibre per 100g, whilst wholegrain bread contains 7-9g.

This lack of fibre means your blood sugar spikes quickly after eating white bread, then crashes within an hour or two, leaving you hungry again. This roller coaster effect leads to overeating and makes weight loss nearly impossible.

The Calorie Problem

Two slices of white bread contain approximately 160-200 calories with minimal nutritional benefit. That’s before you add butter, jam, or sandwich fillings. Compare this to wholegrain bread, which contains similar calories but provides substantially more nutrients, fibre, and sustained energy.

The NHS recommends that adults consume at least 30g of fibre daily, yet the average UK adult consumes only 18g. Switching from white to wholegrain bread is one of the easiest ways to increase your fibre intake whilst supporting your weight loss goals.

Making the Switch to Wholegrains

Fortunately, UK supermarkets now stock extensive varieties of wholegrain and seeded breads, making this one of the easier swaps to implement.

Choosing the Right Wholegrain Bread:

• Look for “wholemeal” or “wholegrain” as the first ingredient
• Check the fibre content (aim for at least 5g per 100g)
• Avoid “brown bread” which is often white bread with colouring
• Choose seeded varieties for extra nutrients and texture
• Try rye, spelt, or granary for variety

Transition Strategy

• Week 1: Replace half your white bread with wholegrain (one slice of each for sandwiches)
• Week 2: Switch to wholegrain for sandwiches, keep white bread for toast
• Week 3: Use wholegrains exclusively but try different varieties to find your favourite
• Week 4: White bread will taste bland and overly sweet by comparison

Pro Tip

Toasting wholegrain bread improves its texture and flavour significantly. Add mashed avocado, poached eggs, or lean protein for a satisfying, nutrient-dense meal that will keep you full for hours.

7. Cream-Based Salad Dressings – Turning Healthy Into Harmful

Salads are universally recognised as healthy meals, yet cream-based dressings can transform your virtuous lunch into a caloric disaster. Caesar, Ranch, Thousand Island, and Creamy Italian dressings are amongst the most popular choices in the UK, but they’re definitely foods you should never eat—or at least, never eat in the quantities most people use.

The Hidden Calorie Bomb

The problem with cream-based dressings is that they pack an enormous caloric punch in a very small serving. Just two tablespoons (the “recommended serving size”) of Ranch dressing contains approximately 120-180 calories, with most of those coming from fat. The reality? Most people use 4-6 tablespoons on a restaurant salad, adding 300-500 calories to what should be a light, healthy meal.

This means your “healthy” chicken salad could contain more calories than a burger, entirely due to the dressing. According to nutritional research, salad dressings are one of the top contributors to hidden calories in seemingly healthy meals.

The Low-Fat Deception

Many people turn to “low-fat” versions of cream-based dressings, thinking they’ve solved the problem. Unfortunately, manufacturers typically replace fat with sugar to maintain flavour and texture. Whilst the fat content decreases, the calorie content often remains similar or even increases due to added sugars and thickeners.

A study comparing regular and low-fat dressings found that low-fat Ranch contained only 15% fewer calories than regular Ranch, whilst containing 40% more sugar. You’re not actually saving meaningful calories—you’re just consuming a different balance of unhealthy ingredients.

Restaurant Portions Are Excessive

When dining out, restaurants typically drench salads in dressing before serving them. A standard restaurant salad often contains 6-8 tablespoons of dressing—that’s potentially 500 calories before you’ve even considered the salad ingredients themselves. This generous pouring happens because restaurants know that customers associate flavour with value, and dressing is cheap.

The Smart Dressing Strategy

You don’t need to eat dry salads for the rest of your life. Instead, switch to oil-based dressings and learn proper portion control.

Healthier Dressing Alternatives

• Extra virgin olive oil and balsamic vinegar (classic and effective)
• Lemon juice with herbs and a touch of honey
• Apple cider vinegar with Dijon mustard
• Tahini dressing (made with sesame paste and lemon)
• Greek yoghurt with herbs and garlic

The Fork-Dipping Method

This technique revolutionises how you enjoy salad whilst dramatically reducing calorie intake. Pour your dressing into a small cup on the side. Before taking a bite of salad, dip your fork into the dressing, then spear your salad. You’ll taste the dressing with every bite whilst using only a fraction of the amount you’d normally pour over the salad.

Making Your Own Dressings

Creating homemade dressings takes just minutes and ensures you know exactly what you’re consuming. A simple vinaigrette requires only three ingredients: three parts oil (olive, avocado, or walnut), one part acid (vinegar or lemon juice), and seasonings to taste. Whisk together and store in the fridge for up to two weeks.

Restaurant Strategy

Always ask for dressing on the side. Most UK restaurants will accommodate this request without question. Use the fork-dipping method or measure out just one tablespoon and mix it through your salad yourself.

Your 30-Day Action Plan

Making all these changes at once can feel overwhelming, so here’s a structured, week-by-week plan to help you gradually eliminate these foods whilst building sustainable, healthy habits. Follow this timeline at your own pace—if you need two weeks instead of one for any step, that’s perfectly fine.

Week 1: Assessment

• Track everything you eat for seven days
• Identify which of these seven foods appears most frequently
• Choose your first food to eliminate (start with fizzy drinks or packaged biscuits)

Week 2: First Substitution

• Remove your chosen food from your shopping list
• Stock up on healthy alternatives
• Use the transition strategies provided for your chosen food

Week 3: Add Movement

• Begin with 10 minutes of daily walking
• Gradually increase to 15-20 minutes
• Movement accelerates weight loss and improves overall health

Week 4: Second Food Elimination

• Choose your second food to remove
• Continue with your first substitution
• Increase daily movement to 25 minutes

Weeks 5-8: Continue the Pattern

• Eliminate one additional food every 10-14 days
• Allow your taste buds time to adjust
• Increase exercise duration by five minutes weekly

By the end of 30 days, you’ll have eliminated 2-3 of these problematic foods and established healthier eating patterns. Continue this gradual approach until you’ve addressed all seven foods on this list.

Final Thoughts: Sustainable Change Over Quick Fixes

These seven foods—fizzy drinks, chips, packaged biscuits, chocolate bars, bacon, white bread, and cream-based dressings—are the hidden saboteurs in your weight loss journey. They’re not “evil” foods that you must avoid forever, but they’re foods you should never eat regularly if you’re serious about losing weight and improving your health.

The beauty of this approach lies in its sustainability. Rather than following a restrictive fad diet that eliminates entire food groups, you’re making targeted, permanent changes. As you eliminate each food one at a time, your body adjusts, your taste preferences evolve, and healthy eating becomes your new normal rather than a temporary sacrifice.

Remember, weight loss isn’t about perfection—it’s about consistency. If you occasionally enjoy a chocolate bar at a special event or have chips whilst on holiday, that’s absolutely fine. What matters is your daily habits, not occasional indulgences.

Start today. Choose just one food from this list to eliminate. Stock up on healthier alternatives. Give yourself permission to take it slowly. Your body—and your waistline—will thank you.