When the actual diets were compared between 2000 to 2016, the trends for fruits and vegetables and starchy foods intake are in line with the modeled diets. The consumption of milk and milk products has gone down between 2000 and 2016, yet both modeled diets show an increase in consumption of dairy. In terms of protein intake, the FBDG diet shows meat and fish intake comparable to the actual diet in 2016; intake for both these groups has increased since 2000 and if this trend continues, i.e., a further increase, it will exceed the dietary recommendation as well as the GHGe contribution.

The EAT Lancet diet suggests almost a doubling of dairy intake, pulses and halving fish and starchy foods compared to the FBDG diet. The implications for such recommendation in a predominantly rice based diet are enormous; perhaps replacing white rice with whole grains/brown rice would assist the shift towards a healthier diet as per the EAT Lancet guidance. Also, the ongoing introduction of fortified rice in social assistance programs increases nutritional value of the diet among a part of the population for whom rice makes up a large component of their diet. The difference between the FBDG and EAT Lancet diets is noteworthy. Even though the direction of change from current diet is similar in both diets, the change is even more pronounced for the EAT Lancet diet, which requires major changes from current food consumption patterns, even more so than the FBDG diet.

# **4.3 Policy considerations**

There are two broad implications to consider from the results of the Bangladesh diet assessment. First, a recent analysis that assessed country specific dietary shifts to mitigate the climate and water crises, while also addressing healthy diets, concluded that achieving healthy and energy and protein adequate diets in many low- and middle-income countries would require an increase in GHGe (Semba 2020). The results from Bangladesh are in line with this conclusion and policy reform and action will require decision making that takes into account that the relationship and interplay between healthy diets, global food systems, and climate is complex and often there are trade-offs. Different environmental aspects can be affected by shifts in dietary change (e.g., land use, biodiversity, anti-microbial use), but in this analysis we have focused on GHGe.

FAO and WHO’s simplified definition of sustainable healthy diets states that: ‘sustainable healthy diets are dietary patterns that promote all dimensions of individuals’ health and wellbeing; have low environmental pressure and impact; are accessible, affordable, safe and equitable; and are culturally acceptable” (WHO and FAO 2019). This definition in many contexts is aspirational as a healthy diet does not always imply that it has minimal environmental impact compared to current diets.

Second, it is important to consider the nutritional objectives and optimal diets across different phases of the lifecycle, which were not modeled in the current analyses. Having a baseline provides a starting point for where and what should increase/decrease nutritionally and to what extent and for whom. For example, if the goal is to prevent undernutrition among pregnant and lactating women and young children, a moderate intake of animal source foods and/or fortified foods and supplements are required to ensure adequate intake of good quality protein, vitamins, and minerals and this will likely increase GHGe (de Pee et al. 2021). Such an analysis would further refine policy action.

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