In a recent study published in the Science of The Total Environment Journal, researchers explored the relationship between the consumption of ultra-processed foods (UPFs) and greenhouse gas (GHG) emissions.
Study: Ultra-processed foods consumption as a promoting factor of greenhouse gas emissions, water, energy, and land use: A longitudinal assessment. Image Credit: Lightspring /Shutterstock.com
UPF are industrial products that are made from food substances or organic sources. UPFs are not essential for a well-rounded diet and encourage excessive consumption, contributing to the growing negative environmental impact.
The production of UPF is a significant contributor to environmental pressures. More evidence is needed to comprehend how UPFs affect health beyond nutrient interactions. The environmental impact of this issue should be considered, in addition to its adverse health effects.
About the study
In the present study, researchers evaluated the impact of a two-year increase in UPF consumption on the environmental effects of the diet.
Eligible individuals included 9,677 contacted individuals, among which 6,874 participants were men aged between 55 and 75 or women aged between 60 and 75. After exclusions, the analysis included a total of 5,879 participants.
At baseline and two-year-follow up, trained dietitians used a validated semi-quantitative 143-item food frequency questionnaire (FFQ) to evaluate typical dietary intakes. The study recorded consumption frequencies using a scale of nine categories ranging from "never or almost never" to "more than six times per day."
The NOVA system categorized the FFQ food items into four established groups. The NOVA classification system categorizes food into four groups: minimally processed or unprocessed foods, processed culinary food products, processed foods, and UPFs.
The study categorized the participants into three groups based on the percentage reduction of UPF intake: tertile 1 (T1) had the highest reduction of UPF intake with a maximum reduction of -3.7839%, tertile 2 (T2) had a medium reduction ranging from -3.7838% to -0.5537%, and tertile 3 (T3) had the lowest reduction with a minimum reduction of -0.5536% or higher.
The study evaluated a 17-item energy-reduced MedDiet questionnaire to confirm adherence to the diet at baseline and after two years without introducing any new information.
The study utilized two validated questionnaires, the Minnesota-REGICOR short physical activity (PA) questionnaire and the Spanish version of the Nurses' Health Study questionnaire, to evaluate physical activity and sedentary behaviors at the beginning and end of two years.
On average, T1 reported a UPF reduction of 8.7%, T2 reported a UPF reduction of 2.0%, and T3 had a UPF increase of 2.4%. The T1 and T2 groups had the highest and moderate %UPF reduction, respectively, and had more men than women. On the other hand, the T3 group, which had the lowest %UPF reduction, had more women than men.
The study found that T1 participants reduced their intake of red and processed meat, sweets, and pre-cooked products. They also increased their consumption of fruits and vegetables and slightly increased their fish, white meat, and nuts intake.
T3 had a higher reduction in dairy intake compared to T1 and T2. However, there was a lower decrease in the consumption of pre-cooked and red and processed meat products in T3. The participants in T3 also consumed fewer fruits and vegetables and slightly more sweets.
Furthermore, in T1, there was an average rise of 156.2 g of unprocessed foods and a mean decrease of 196.3 g of UPF. However, in T3, there was an average decrease of 70.8 g of unprocessed foods and an increase of 48.7 g of UPF.
T1 participants achieved more significant GHG emissions and energy consumption reductions than other groups, although water usage increased over time. Consuming more UPF would lead to higher GHG emissions and energy usage but decreased water usage in both years.
An increase in the UPF proportion consumed may result in lower water usage but higher energy intake and CO2 emissions at the two-year follow-up compared to the baseline.
The study suggests that reducing consumption of ultra-processed foods can help promote environmental sustainability by lowering greenhouse gas emissions and energy use. However, it may lead to an increase in water usage.
Processed meat consumption was identified as a critical factor contributing to the environmental impact of UPFs among study participants.
The study found that those who decreased their consumption of UPFs also tended to reduce their red and processed meat intake.
The study suggests that moderate consumption of white meat or fish could be a viable alternative to UPF. Eating cereals, legumes, fruits, and vegetables in proportion to one's energy requirements can positively impact personal health and the environment.
Consideration of the processing threshold of food is essential for nutritional guidance and environmental conservation.