# **1 Introduction**

Diets around the world deviate from what is healthy, nutritious, and sustainable. Overall people are eating poorly; diets are dominated by refined grains and high-fat and/or high-sugar foods, unhealthy oils and beverages, and inadequate amounts of nutritious foods such as fruits, vegetables, legumes, nuts, fish, dairy, eggs, and whole grains. Unsustainable diets indicate that environmental costs are significant externalities not integrated into the current value of diets. This proposed work will describe the quality of diets in Bangladesh considering both the nutritional value and environmental cost of the diet and how these compare to dietary guidelines. As such, this paper describes the dietary changes needed in the country and can help in the design of policy and investment options towards such change.

The EAT-Lancet report assessed global food consumption and production against human health targets and planetary health boundaries (Willet et al. 2019). The report simulated the impacts of three actions, namely change in production practices, change in diets, and halving food loss and waste. A set of two key targets were identified in that report. The first is to achieve the _planetary health diet_ through dietary shifts. Such a shift would avert 10.8 million adult deaths per year. The second target is to transition into sustainable food production which limits six earth system processes: climate change (GHGe), land-system change (cropland use), freshwater use, nitrogen cycling, phosphorous cycling, and biodiversity loss (extinction rate). However, the idea of a single planetary health diet is tenuous, and even so the path towards positive dietary change will vary across countries and require a transformation of the food systems. For example, current diets lack diversity and the shift to healthier sustainable diets will require in many low- and middle-income countries an increase in GHGe and water use due to food production (Kim et al. 2020). The cheapest planetary health diet costs US$2.84 per day, exceeding the household per capita income of 1.58 billion people (Hirvonen et al. 2020) and food expenditure of many more. More than 3 billion people in the world cannot afford a healthy diet (Herforth et al. 2020).

This suggests that more careful analysis at the country level, and particularly among developing countries, is needed to identify a benchmark healthy, nutritious, and sustainable diet in that context, thereby setting long-term targets and aligning adequate strategies both from the supply and demand sides. This will help gauge the gap between current diets and this benchmark diet, and to assess how best to close this gap. More recently, such country-level work has been done in India (Chaudhary 2019; Sharma et al. 2020) and in Indonesia (de Pee et al. 2021). Building on this emerging literature, the focus of this paper is to assess the gaps of Bangladeshi diets against an example of a healthy sustainable benchmark—the EAT Lancet diet and to Bangladesh’s food based dietary guidelines (FBDG).

Diets in Bangladesh have been changing over time, albeit slowly (Waid et al. 2017). Over the 25 years from 1985 to 2010, the consumption of starches and pulses have decreased by seven percent and 32 percent, respectively. In contrast, consumption of other foods has increased. Over the same period, fruit consumption increased by 91 percent, vegetables by 24 percent, eggs by 67 percent, meat by 124 percent, and oils by 169 percent. Yet current diets still fall below the nutritionally recommended diets, or national dietary guidelines (Dizon et al. 2020). In 2016, consumption of starchy staples was still too high, at 137 percent of the recommended amount. On the other hand, 2