Epsilon Archive for Student Projects

Abstract

This master’s thesis examined whether replacing cow’s milk with fortified oat and pea drinks in the Swedish adult diet could make Sweden’s food system be in accordance with the planetary boundaries defined in the EAT-Lancet Commission Framework. It also evaluated the nutritional consequences of this dietary substitution. Using life cycle assessment and material flow analysis, three scenarios for transitions with different combinations of oat and pea drinks were modeled and compared to a 2023 business-as-usual scenario for the Swedish adult population. Scenarios were assessed across the six EAT-Lancet Earth system processes (climate change, land-system change, nitrogen cycling, phosphorus cycling, freshwater use, and biodiversity loss), food waste across the supply chain and contributions to nutrient intake.
To support household food waste estimations, a small-scale sensory test was conducted to challenge the maximum drinkability window of the drinks. Household losses were then estimated based on the share of consumers relying on best-before dates (32 %), sensory information such as taste, smell, and appearance (26 %), and handling errors (42 %). These proportions were combined with data on surplus volumes around the best-before date and the outcomes of the sensory test. Oat and pea drinks lasted 20 and 24 days, respectively, after opening, compared to 10 days for fresh milk after opening. Since plant-based milk alternatives are UHT-treated when unopened, they remain stable until opening, while milk is affected by its fresh-product packaging. An analysis of drink losses in the entire systems showed that households were the main contributors to waste, and that total drink losses decreased by 25–30 % when replacing milk with plant-based milk alternatives.
The results showed that all plant-based test-cases had lower impacts on Earth system processes than the dairy-dominated base-case. Annual greenhouse gas emissions decreased from 1.0 to 0.5 Mt CO2e, land-system change from 150 to 72, 81, and 63 ha, nitrogen application from 35 to 12, 11, and 13 t, phosphorus application from 1.1 to 0.4 kg, freshwater use from 4.1 to 3.3, 2.9, and 3.6 m3, biodiversity loss from 4.5 · 10–7 in the base-case to 2.2 · 10–7 and 2.4 · 10–7 E/MSY (extinctions per million species-years), in test-cases 1-3, respectively.
When the whole diet was assessed on a per-capita basis and compared to the 2023 global targets, all Earth system processes exceeded the safe limits except for freshwater use. Climate impact reached 2.2 tons of CO2e per capita, well above the global 0.6 tons of CO2e target, indicating major overshoot. Land-system change was 0.24 m2 per capita, exceeding the global 0.16 m2 target with moderate overshoot. Nitrogen application ranged from 49–52 kg N, far above the global 11 kg N target, and phosphorus application was 4.6 kg P, exceeding the global 1.0 kg P target – both with major overshoot. Freshwater use remained within the safe space at 49 m3 per capita, below the global 309 m3 target. Biodiversity loss reached 7.8 · 10–9 E/MSY, surpassing the global 1.2 · 10–9 E/MSY target, with major overshoot. As milk alone accounts for a relatively small portion of total dietary emissions, addressing only milk is insufficient; other components of the diet must also reduce their unsustainable resource use.
Substituting milk with oat and pea drinks can be nutritionally viable on a population-level. Oat and pea drinks provided most of the micronutrients typically supplied by milk, in similar amounts, including calcium, vitamin D, vitamin B2, and vitamin B12. However, they contained only about half the protein and lacked certain essential amino acids.
Replacing milk with fortified oat and pea drinks improves sustainability and lowers food waste but is not enough to align with planetary boundaries. Achieving this goal will also require broader dietary shifts, technological innovation, and systemic reductions in waste.