Ultra-Processed Foods and Metabolic Health: The Evidence

Quick answer

Ultra-processed foods (UPFs) are linked to a higher risk of type 2 diabetes, obesity and heart disease. One small trial found people ate more when the food was ultra-processed. Large studies show association, not proof of cause. Choosing more minimally processed food is a reasonable step, and tracking what you eat helps you see where UPFs show up.

Introduction

From protein bars to “healthy” cereals, ultra-processed foods are everywhere. They are cheap, convenient and designed to be easy to eat. This guide covers what counts as a UPF, what the research does and does not show, and how to cut back without guesswork.

What are ultra-processed foods?

UPFs are a category in the NOVA food classification. They are industrial formulations made from food substances and additives. A practical test is the ingredient list. If it contains an item rarely used in home kitchens, the product is likely ultra-processed. The NOVA authors give high-fructose corn syrup, hydrogenated oils and hydrolysed proteins as examples. Another sign is a cosmetic additive such as a flavour, colour, emulsifier, sweetener or thickener (Monteiro et al., 2019).

Examples:

• Sweetened breakfast cereals
• Packaged snacks and chips
• Soft drinks and energy drinks
• Instant noodles and many ready meals

Not all processing is the same:

• Minimally processed: frozen vegetables, plain yogurt, dried beans
• Processed: canned beans, cheese, simple bread
• Ultra-processed: soda, most packaged snacks, many fast foods

What the research shows

Eating more

In a 2019 NIH trial, 20 adults lived in a research unit. They ate an ultra-processed diet for 2 weeks and an unprocessed diet for 2 weeks, in random order. Meals were matched for presented calories, energy density, macronutrients, sugar, sodium and fiber. On the ultra-processed diet, people ate about 508 kcal more per day and gained about 0.9 kg. On the unprocessed diet they lost about 0.9 kg (Hall et al., 2019). The trial was small and short, so it shows what can happen, not what happens over years.

Type 2 diabetes

A 2022 meta-analysis pooled 18 long-term studies with about 1.1 million people. Moderate UPF intake was linked to a 12% higher risk of type 2 diabetes, and high intake to a 31% higher risk (Delpino et al., 2022).

Wider health outcomes

A 2024 BMJ umbrella review covered 45 pooled analyses and almost 10 million people. Higher UPF intake was linked to higher risks of type 2 diabetes, cardiovascular death, anxiety and common mental disorders. It was also linked to higher all-cause mortality and obesity. For type 2 diabetes, the dose-response risk ratio was 1.12. Most of the evidence was rated low or very low quality under GRADE (Lane et al., 2024).

A 2025 Lancet review concluded that the overall evidence supports a link between UPF-heavy diets and chronic disease. It pointed to overeating, poor nutrient balance and food additives as possible reasons (Monteiro et al., 2025).

Limits of the evidence

• Most large studies are observational. People who eat many UPFs may differ in other ways, such as income, activity and smoking.
• Food questionnaires are imprecise, and UPF definitions vary between studies.
• The only trial above is small and ran for 4 weeks in total.
• It is still unclear which feature of UPFs matters most: the nutrients, the texture, the additives or the way they are eaten.

How to spot UPFs, including the “healthy” ones

• Long ingredient lists with items you would not stock at home
• Flavours, sweeteners, emulsifiers or thickeners on the label
• Health claims on the front, such as “high protein” or “zero sugar”

Foods that are often ultra-processed even when marketed as healthy include some granola bars, flavored yogurts, plant-based meat substitutes and protein snacks. Check the ingredient list rather than the front of the pack.

Practical swaps

Ultra-processed example	Swap for
Flavored instant oatmeal	Rolled oats and berries
Protein bar	Plain yogurt and nuts
Soda or energy drink	Sparkling water and citrus
Packaged chips	Air-popped popcorn
Sweetened cereal	Overnight oats and seeds
Frozen pizza	Whole-grain wrap and vegetables

For more meal ideas, see our blood sugar food guide and our nutrition strategies for metabolic health.

Tracking UPFs with Helsa

Helsa lets you log meals by photo or barcode. Looking back over your logs can show where packaged foods creep in. If you also track glucose or weight, you can compare those with your food log. This is a personal record, not proof of cause.

Key takeaways

• Higher UPF intake is linked to more type 2 diabetes, obesity and heart disease in large studies.
• The link is an association, and most of the evidence is low quality.
• One small trial found people ate about 500 kcal more per day on a UPF diet.
• Reading ingredient lists and choosing minimally processed foods more often is a simple, low-risk step.

This article is for information only. It is not medical advice.

References

1. Monteiro CA et al. Ultra-processed foods: what they are and how to identify them. Public Health Nutr. 2019. PubMed
2. Hall KD et al. Ultra-processed diets cause excess calorie intake and weight gain: an inpatient randomized controlled trial of ad libitum food intake. Cell Metab. 2019. PubMed
3. Delpino FM et al. Ultra-processed food and risk of type 2 diabetes: a systematic review and meta-analysis of longitudinal studies. Int J Epidemiol. 2022. PubMed
4. Lane MM et al. Ultra-processed food exposure and adverse health outcomes: umbrella review of epidemiological meta-analyses. BMJ. 2024. PubMed
5. Monteiro CA et al. Ultra-processed foods and human health: the main thesis and the evidence. Lancet. 2025. PubMed