Ultra-processed food, sugar, juice: what really counts

The NOVA classification sorts foods into four groups. Ultra-processed foods are industrial formulations, often with ingredients rarely used at home, such as flavours, emulsifiers or sweeteners.^[1]

It is not easy to apply: French specialists sorting over 100 foods reached only low agreement.^[2] The DGE says that uniform criteria are missing and points out that packaged wholegrain bread or fruit yoghurt can fall under it too.^[3]

In a clinic study of 20 adults, participants ate 508 kcal more a day on an ultra-processed diet when they could eat freely. The study was small and short, and the food was more energy dense.^[4]

A British study of 55 people tested this in daily life for 8 weeks each. Both diets followed nutrition guidelines, weight fell on both, slightly more on minimally processed food, a difference of about 1 kg.^[5]

Observational studies see many links with disease, but the evidence is mostly weak.^[6] It also depends on what is meant: sugar-sweetened drinks and meat products stand out most, wholegrain bread or yoghurt rather not.^[7][8]

Whether processing itself is the problem has not been settled. Many of these products are simply high in energy, salt or sugar.^[8] The S3 guideline therefore specifically advises limiting ultra-processed foods with high energy density.^[9]

The WHO advises keeping free sugars under 10% of energy and suggests under 5%. Free means added sugar plus sugar in honey, syrups and juice, not in whole fruit.^[10] German societies adopt the 10% as a maximum, which at 2,000 kcal is about 50 g a day.^[11]

EFSA could not set a safe upper limit and says added and free sugars should be as low as possible. When sugar replaces other nutrients at equal calories, studies show no harm for weight. So it is mainly about the energy.^[12]

These are means from the German product monitoring 2024, single products differ.^[13] A 200 ml glass of apple juice has about 92 kcal, a glass of lemonade or cola about 85 kcal.^[14]

Drinks often fill you less than food. In a small study of 15 people, they made up for calories from sweets at meals, but not for calories from soda.^[15] This is no law, as a review of 253 tests found very mixed results.^[16] In studies of adults, weight went up by about 0.8 kg when sweetened drinks were added and down by about 0.5 kg when they were removed.^[17] The S3 guideline clearly advises limiting them.^[9]

The DGE sees juice as an extra on top of five portions of fruit and vegetables, two 200 ml glasses a week, or as a spritzer with three parts water. Smoothies are concentrated. Both give less fibre and fill you less than whole fruit.^[18]

In a trial of 58 adults, a whole apple before a meal lowered intake, apple juice less so.^[19] On weight, the data on juice are mixed: studies in adults showed no confirmed effect.^[20] So juice is no poison, it just counts.

• Start with drinks, where change is easiest. Water and unsweetened tea are the simplest choice. There is more on diet drinks under Sweeteners and sugar alcohols.
• Look less at the label “ultra-processed” and more at how often something very energy-rich is on the table.
• None of this has to go completely. Bans rarely last, see Cravings.