Packaged snacks, sweet drinks, and quick meals are easy to find in cities across Kenya and East Africa — at supermarkets, kiosks, and street stalls. At the same time, many families hear conflicting messages about what is “healthy.” Large studies cannot tell any one person exactly what will happen to them, but they can show patterns across whole populations. A major 2024 review in The BMJ brought together many earlier summaries of the research to give a clearer picture of how diets rich in ultra-processed foods line up with various health outcomes.
What are ultra-processed foods (and NOVA)?
Ultra-processed foods are one category in the NOVA system, which sorts foods by how much they are industrially transformed. In plain terms, UPFs are often made from ingredients you would not typically use at home (for example industrial starches, protein isolates, or additives for colour, flavour, or shelf life) and tend to contain long ingredient lists with little intact whole food. They are designed to be convenient, palatable, and stable — not “evil,” but a useful label for a type of food pattern researchers can measure.
Familiar examples in many African urban settings might include packaged sweet or salty snacks, sugary soft drinks and powdered mixes, instant noodles, or industrial breads and spreads — without naming specific brands. Many traditional dishes cooked at home from whole ingredients are not ultra-processed in this sense; the question is how much of what you eat week to week falls into the industrial, heavily formulated group.
What kind of study was this?
An umbrella review does not recruit new volunteers. It summarises existing systematic reviews and meta-analyses — that is, studies that already pooled results from many individual papers. Most of the underlying research is observational (cohorts, case-control, or cross-sectional designs): people are grouped by how much UPF they tend to eat, and outcomes are compared over time. That can reveal associations at the population level; it does not by itself prove that UPF causes disease in one person.
What the BMJ umbrella review found
Researchers searched MEDLINE, PsycINFO, Embase, and the Cochrane Database of Systematic Reviews, plus reference lists, from 2009 to June 2023. They applied preset rules to grade how strong the epidemiological evidence looked (convincing “class I”, highly suggestive “class II”, suggestive “class III”, weak “class IV”, or no evidence “class V”), and they also rated GRADE quality (from high to very low) for each pooled analysis.
According to the published results:
- The search identified 45 unique pooled analyses, including 13 dose-response associations and 32 non-dose-response associations, involving 9,888,373 participants.
- Direct associations were reported between exposure to ultra-processed foods and 32 (71%) of the health parameters examined, spanning mortality, cancer, and mental, respiratory, cardiovascular, gastrointestinal, and metabolic outcomes.
Evidence graded as convincing (class I) supported direct associations between greater ultra-processed food exposure and:
- higher risk of incident cardiovascular disease related mortality (risk ratio 1.50, 95% confidence interval 1.37 to 1.63; GRADE very low);
- higher risk of type 2 diabetes in a dose-response analysis (risk ratio 1.12, 1.11 to 1.13; GRADE moderate);
- higher odds of prevalent anxiety outcomes (odds ratio 1.48, 1.37 to 1.59; GRADE low);
- higher odds of combined common mental disorder outcomes (odds ratio 1.53, 1.43 to 1.63; GRADE low).
Highly suggestive (class II) evidence was reported for direct associations with, among others:
- incident all cause mortality (risk ratio 1.21, 1.15 to 1.27; GRADE low);
- heart disease related mortality (hazard ratio 1.66, 1.51 to 1.84; GRADE low);
- type 2 diabetes in another pooled analysis (odds ratio 1.40, 1.23 to 1.59; GRADE very low);
- depressive outcomes (hazard ratio 1.22, 1.16 to 1.28; GRADE low);
- prevalent adverse sleep related outcomes (odds ratio 1.41, 1.24 to 1.61; GRADE low);
- wheezing (risk ratio 1.40, 1.27 to 1.55; GRADE low);
- obesity (odds ratio 1.55, 1.36 to 1.77; GRADE low).
Of the remaining 34 pooled analyses, 21 were graded suggestive or weak (class III–IV) and 13 as no evidence (class V). Overall, using GRADE, 22 pooled analyses were rated low quality, 19 very low, and four moderate.
The authors concluded that greater exposure to ultra-processed food was associated with a higher risk of adverse health outcomes, especially cardiometabolic, common mental disorder, and mortality outcomes, and that findings support further population-level measures and mechanistic research — not panic, but a public-health signal.
Limitations worth remembering
These results still leave room for residual confounding: people who eat more UPF often differ in income, stress, sleep, smoking, activity, and overall diet quality, and those factors are hard to fully separate in data. How foods are classified with NOVA is also debated among scientists — two researchers might disagree on the category for a given product. The numbers describe groups, not your personal risk. Association is not destiny for any individual.
What to eat more of (big-picture guidance)
For “what to emphasise” rather than only what to limit, many national and global bodies — including the World Health Organization — encourage patterns rich in vegetables, fruits, legumes, whole grains, and minimally processed foods, with attention to salt, sugar, and healthy fats. Check Kenya’s or your country’s official dietary guidelines for local, practical advice.
What you can do — small, realistic steps
Perfection is not the goal. Busy schedules, tight budgets, and limited kitchen space mean many people cannot avoid all ultra-processed foods, and that is understandable.
- Cook at home a little more when you can — even simple staples with vegetables, beans, or lentils — so UPF becomes a smaller share of the week.
- Choose simpler foods when shopping: shorter ingredient lists and foods that look closer to how they grew or were traditionally prepared.
- Prioritise water over sugary drinks; save sweet beverages for occasional treats if you enjoy them.
- Add vegetables, greens, and pulses to meals you already make (stews, ugali sides, rice dishes) rather than overhauling your diet overnight.
- Glance at labels for sugar and salt when you have a moment at the shop.
- Change one habit at a time — for example one fewer daily soda, or one extra home-cooked dinner — and build from there.
Over months and years, patterns matter more than a single meal. Small shifts can add up. For personal targets (weight, diabetes, blood pressure, mental health, or pregnancy), speak with a clinician or registered dietitian who knows your history.
Sources
- Lane MM, Gamage E, Du S, et al. "Ultra-processed food exposure and adverse health outcomes: umbrella review of epidemiological meta-analyses." BMJ 2024;384:e077310. DOI: 10.1136/bmj-2023-077310.
- Read the open-access article and linked editorial on The BMJ for full methods, figures, and discussion.
Remember: Tabibu Health provides health information only. Always consult a qualified healthcare professional for diagnosis, treatment, and personalized advice.