Glossary: D

Here you will find definitions of terms used in resources on the Foodsource website. You will also find these definitions on the right-hand side within chapters. If you have any suggestions for new glossary items, let us know here.

2 (1) | A (12) | B (5) | C (16) | D (4) | E (8) | F (12) | G (4) | H (3) | I (6) | L (5) | M (12) | N (6) | O (4) | P (9) | R (8) | S (9) | T (1) | U (2) | W (4) | Y (1) | Z (1)

Decoupling (or eco-economic decoupling)

This concept is used to refer to the idea of disconnecting the growth of gross domestic product (GDP) from increases in environmental impacts – climate change in particular. The term is sometimes used more broadly in relation to overall human well-being rather than GDP. The idea of decoupling is based on the understanding that economic growth often goes hand in hand with increases in environmental impacts. Advocates of decoupling think that advances in technology will provide ways of fostering economic growth without increasing the use of resources or the generation of environmental impacts, and without requiring radical shifts in aspirations as to what constitutes a ‘good’ standard of living. Decoupling can be used both in a relative sense (e.g. a lower ratio of environmental impacts versus GDP) and in an absolute sense (i.e. the overall amount of environmental impacts is reduced). Relative decoupling is sometimes criticised for being open ended and thereby failing to speak to the need of keeping production and consumption levels within environmental limits. In general, critics question whether decoupling (both relative and absolute) is feasible for diverse reasons: because of the possibility of rebound effects; because it is unlikely to be possible to separate the production of goods and services from resource use (and the impacts of this resource use) to the degree that is necessary; and because the growth-based economic paradigm on which faith in decoupling is based fails to challenge the potential insatiability of human demand – an insatiability which (it is argued) lies at the root of our environmental crisis.


Desertification refers to a process by which fertile land becomes desert; this can be due to deforestation, drought or inappropriate agriculture methods.

Dietary survey

The term 'dietary survey' refers to a group of methods that are used to collect food consumption data to study the diets of individuals or groups. Common methods in dietary surveys are food frequency questionnaires, food diaries, and 24-hour recalls. These are often combined with the weighing and analysis of food to determine its nutritional properties. Dietary surveys are sometimes combined with other methods (e.g. the measurement of BMI or blood values) to study the relations between certain dietary patterns and health outcomes. National dietary surveys, conducted and commissioned by national and international health authorities, study national dietary patterns and are often an important input for the development of food policy.

Disability-Adjusted Life Years (DALYs)

Disability-Adjusted Life Years (DALYs) are a way of measuring the burden of ill health. One DALY can be thought of as one lost year of healthy life. Across a population, DALYs are calculated by adding together years of life during which illness is experienced, weighted according to the severity of the illness, and years of life lost to premature mortality.