Why I Don't Eat Supermarket Bread — A Year Without Ultra-Processed Food

Introduction

I stopped eating supermarket bread a year ago.

Paying closer attention to sugar made me more aware of everything else I was eating. When I finally looked properly at the ingredients in a loaf of Warburtons, bread I had eaten for years, I realised how little thought I had ever given to it.

This is not about singling out one company. Warburtons is simply the example I know best because it is what I ate. The same ingredients and shortcuts appear across most supermarket bread. For a long time, I did not notice this. Now I do.

I am not saying I will never eat supermarket bread again. I now treat it the same way I treat junk food — something to be aware of and eat accordingly. This post is about bringing awareness to what is in the bread most people eat without thinking.

What this post covers
Why supermarket bread is made the way it is, why certain ingredients matter when eaten regularly, and how sourdough and freezing fit into how I eat now.

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Context

Ultra-Processed Food

More than half of the calories consumed by UK adults come from ultra-processed foods. For adolescents, that figure rises to nearly two-thirds. The UK is the second largest consumer of ultra-processed food globally, behind only the United States.

Ultra-processed foods are not just unhealthy in the traditional sense of being high in fat or sugar. They are industrially manufactured products made by breaking down whole foods into chemical constituents, then reassembling them with additives that would not exist in a home kitchen.

A 2024 umbrella review published in The BMJ analysed 45 pooled studies covering nearly 10 million participants. The findings were stark:

• 50% increased risk of cardiovascular disease-related death
• 48–53% higher risk of anxiety and common mental disorders
• 12% greater risk of type 2 diabetes
• 21% greater risk of death from any cause
• 22% increased risk of depression

The researchers graded this evidence as “convincing” — the highest classification.

Bread as a Case Study

Packaged bread is one of the most common ultra-processed foods in the UK diet. It is so familiar that most people do not even think of it as processed. A 2024 UK study found that many consumers perceive packaged bread as relatively healthy because of how common it is, and do not place it in the same category as more obvious junk food.

The ingredients tell a different story.

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Supermarket Bread

For years, I ate Warburtons 800g Toastie. Three or four slices a day with breakfast. The packaging calls it “the hero of our brand new campaign” and promises it will “set you up for the day.”

I never questioned it. Then I read the label.

Ingredients

Ingredient	What It Is	Why It Is There
Wheat Flour	Base ingredient	Fortified with calcium, iron, niacin, thiamin
Water	Hydration	Standard
Yeast	Leavening agent	Standard
Salt	Flavour	Standard
Vegetable Oils	Rapeseed and palm oil	Softness, shelf life extension
Soya Flour	Processed protein	Texture, volume, cheaper than wheat
Calcium Propionate	Preservative (E282)	Prevents mould — makes bread last a week
E472e	Emulsifier (DATEM)	Strengthens gluten, improves texture
E481	Emulsifier (SSL)	Softness, uniform crumb structure
Ascorbic Acid	Flour treatment agent	Speeds up dough development

That is ten ingredients for something that needs four: flour, water, salt, yeast.

Nutrient	Per Slice (47g)	Three Slices
Calories	116 kcal	348 kcal
Carbohydrates	22g	66g
Sugars	1.4g	4.2g
Protein	4.3g	12.9g
Fibre	1.1g	3.3g
Salt	0.46g	1.38g

At three slices, which was a normal breakfast for me at the time, that comes to 66g of carbohydrates and over 4g of sugar before anything is added on top.

Health Context

I am not a scientist. The research on these additives was clear enough for me to make a decision and remove them from my diet.

Calcium Propionate (E282)

This is what allows bread to last a week on the shelf. Real bread goes stale in two or three days.

Calcium propionate is a preservative that stops mould growth. Research shows that even small amounts can trigger hormonal responses linked to blood sugar regulation. In controlled studies, propionate intake increased glucose, stress hormones, and insulin counter-regulatory activity. Other trials have linked regular exposure to behavioural changes in children and disruptions to gut bacteria.

The ingredient that keeps bread from going mouldy may be interfering with metabolism and gut function when eaten regularly.

E472e and E481

These emulsifiers are added to keep bread soft, uniform, and consistent at scale. They strengthen gluten and improve texture. They are not added for nutrition.

Large population studies have linked higher intakes of common bread emulsifiers with increased risks of cardiovascular disease and type 2 diabetes. Experimental research also shows that emulsifiers can disrupt gut bacteria and weaken the protective lining of the gut.

In animal studies, these changes alone were enough to trigger inflammation and metabolic dysfunction, even without changes to diet or calories.

The Gut Connection

The common thread in this research is the gut.

Gut bacteria play a role in metabolism, immune function, and inflammation. When emulsifiers alter that bacterial balance, the effects extend beyond digestion. In laboratory studies, gut bacteria taken from emulsifier-fed animals caused inflammation and metabolic symptoms when transferred to healthy animals. The damage was carried in the microbiome itself.

This is what made the ingredient list impossible for me to ignore.

The question I started asking
If real bread needs four ingredients and goes stale in three days, why am I eating something with ten ingredients that lasts a week? What is that extra chemistry doing inside my body?

The Bowel Cancer Connection

In December 2024, Cancer Research UK reported that early-onset bowel cancer is now a “global phenomenon,” with England experiencing the fourth fastest rise in rates among younger adults.

The researchers noted that in many countries, increases in early-onset bowel cancer coincide with periods of economic development and rapid changes in lifestyle and diet. The UK shows the same relationship.

I am not claiming that supermarket bread causes cancer. The research is not there to make that claim. When I see rising rates of bowel cancer in younger adults, alongside research linking ultra-processed foods to gut inflammation, microbiome disruption, and metabolic disorders, I ask myself whether the convenience is worth the risk.

For me, it was not.

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What Changed for Me

Bloodwork

I cannot isolate the effects of removing supermarket bread from other changes I made over the same period, including improving overall diet quality. I had a full blood test done in both 2024 and 2025. The table below shows only the markers most relevant to diet quality, inflammation, and metabolic stress.

Marker	2024	2025	Interpretation
CRP (inflammation)	2.8 mg/L	1.2 mg/L	Reduced systemic inflammation
ALT (liver enzymes)	52	35	Lower liver enzyme levels, reduced metabolic burden
RDW	14%	12.4%	Improved red blood cell consistency

These were the most relevant changes. They moved in the same direction as the dietary changes I made.

Eating Approach

Removing ultra-processed foods was part of a broader shift in how I approach food. I rarely eat out now. I cook most of my meals and focus on nutrient-dense, minimally processed ingredients. One example is a pan-seared chicken with rotating vegetable sides that I eat regularly — high protein, low carb, one pan.

That does not mean perfection. I still eat the occasional cake or biscuit. The difference is that most of what I eat now is simple, minimally processed food. I buy bread from local bakeries and avoid ultra-processed sweets and packaged desserts. The aim is not restriction, but consistency.

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Why Sourdough and How I Eat Now

Criteria

After a year of seeking out proper bread, my criteria are simple:

1. Minimal ingredients — Four to six, ideally organic
2. No preservatives — If it does not go stale, I do not want it
3. Local bakeries or farmers markets — I ask questions, I read labels
4. Sourdough fermentation — Better digestibility, lower glycaemic impact

Lower glycaemic impact
Slower digestion leads to more stable blood sugar levels, reduced insulin demand, and greater metabolic stability over time.

I do not buy supermarket sourdough either. Most of it is fake — regular bread with added vinegar for tang. If there is no starter culture or long fermentation listed, it is not real sourdough.

Bakery

I get my eggs from Notting Hill Farmers Market every week. Today I came across Oliver’s Bakery, based out of Surbiton.

No preservatives. No GMOs. Organic flour. Proper sourdough fermentation.

This is what I have been looking for.

Breads

After looking into how each one is made, I decided these three fit how I eat and train.

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Pain au Levain — White Sourdough

View on Oliver’s Bakery

The quintessential French sourdough — described as “the artisanal baker’s calling card.”

Ingredient
Organic White Flour
Water
Organic White Sourdough
Sea Salt

Four ingredients. Compare that to ten in Warburtons.

Rationale:

• Cleanest ingredient list of any bread I have found
• Light loaf with rich flavour from slow fermentation
• Best digestibility — no bloating, no heaviness post-gym
• Freezes perfectly, toasts perfectly
• Fast recovery carbs for training days

This is my default.
If I am buying one loaf, it is Pain au Levain. Slice, freeze, toast from frozen.

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Pain de Campagne — Country Bread

View on Oliver’s Bakery

Country bread — “both elegant and rustic, slowly fermented for a thick crusty exterior.”

Ingredient
Organic White Flour
Organic Rye Flour
Water
Sea Salt
A Little Yeast

Five ingredients. The addition of rye brings more minerals and fibre without heaviness.

Rationale:

• Rye adds iron, magnesium, and B vitamins
• Still light enough for post-workout
• Thicker crust, excellent texture after freezing
• Works well with eggs, red meat, or hearty meals

Use when increased nutritional density is desired.
Emphasises additional fibre and micronutrients with balanced digestion.

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Wholemeal Sourdough — Satiety Option

Top healthy bread choice — naturally fermented, fibre-rich, and yeast-free.

Ingredient
Organic Wholemeal Flour
Water
Organic Wholemeal Starter
Cracked Wheat
Jumbo Oats
Black Treacle
Honey
Sea Salt

Eight ingredients. More complex than white loaves, but all whole foods.

Rationale:

• Highest fibre content for gut health and appetite regulation
• Slower carbohydrate absorption and steadier blood glucose response
• Greater mineral density from whole grains (iron, magnesium, zinc)
• Naturally fermented with no commercial yeast
• Freezes well and performs reliably when toasted from frozen

Use on rest days or lighter training days.
Prioritises satiety, gut health, and sustained energy rather than rapid recovery.

These are the breads I found that work for me. The point is not to copy this exactly, but to find local bakeries that meet the same criteria — minimal ingredients, no preservatives, proper fermentation. Ask questions, read labels, and find what fits your routine.

What to look for

• Four to six ingredients, ideally organic
• No preservatives — if it lasts a week, question it
• Sourdough starter or long fermentation listed
• No added sugar or emulsifiers
• Local bakery or farmers market — ask questions, read labels

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Freezing

I freeze sourdough for two reasons: practicality and how it affects digestion.

I eat one slice with breakfast. That is it. A fresh loaf would go stale long before I finished it. Freezing means I take exactly what I need, when I need it, without waste.

Freezing also fits how sourdough is made. Long fermentation already slows digestion. When sourdough is frozen, then toasted and allowed to cool briefly, it can further reduce glycaemic impact by increasing resistant starch. That leads to steadier blood sugar and better appetite control compared to eating it fresh and hot.

Step	Action
1	Slice the bread before freezing
2	One loaf per heavy freezer bag
3	Baking paper between slices (optional, prevents sticking)
4	Label the bag (Levain, Campagne, Wholemeal)

Daily Routine

My routine is simple:

1. Toast straight from frozen
2. Pair with eggs (I get mine from the same market)
3. Let the toast cool for one to two minutes before eating

Why let it cool?
Cooling allows resistant starch to form, which is better for blood sugar response and digestion. Small things compound.

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Quick Reference

Loaf	Ingredients	Use Case
Pain au Levain	4	Training days, daily use
Pain de Campagne	5	Extra nutrition, hearty meals
Wholemeal Sourdough	8 (whole foods)	Rest days, satiety, fibre

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Final Thoughts

I am not saying Warburtons is poison. I am saying that for years I ate it without knowing what was in it, and when I found out, I made a different choice.

The UK has some of the highest ultra-processed food consumption in the world. We also have rising rates of obesity, type 2 diabetes, inflammatory bowel disease, and early-onset bowel cancer. Correlation is not causation — but the research is mounting, and I would rather not be the experiment.

Real bread has four ingredients. It goes stale in three days. It does not need a chemistry degree to understand the label.

That is what I eat now.

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Summary

Component	My Approach
Supermarket bread	Cut out completely
What I buy	Sourdough from local bakeries and farmers markets
What I look for	Minimal ingredients, organic flour, no preservatives
Current source	Oliver’s Bakery — Notting Hill Farmers Market
How I store	Sliced and frozen in labelled bags
How much I eat	One slice with breakfast

One year without supermarket bread. My inflammation markers dropped. My liver function improved. The changes were measurable.

These are the breads I found that work for me. The point is not to copy this exactly, but to find local bakeries that meet the same criteria.