The fat and sugar content of contemporary diets and of processed foods, in particular, is a high profile issue for consumer groups, the media and health professionals. There is also increasing pressure from public health bodies and governments to reduce the amounts of fats and sugars, along with salt, in our diet. However, there may be unexpected consequences of such changes as our bodies may respond not only to the presence of these substances in our diets but also their absence, following a dietary manipulation. Withdrawal of dietary components has the potential to influence future food choices and also our emotional health. Generic, calorie restriction, and weight loss diets usually fail to produce the desired long-term outcomes, but increased awareness of the effects of the composition of our diet over both the short and the long term may increase our ability to adapt our diets successfully to improve both metabolic and emotional wellbeing.
Anxiety is linked to prevalence of disease. People with mood disorders often have poor quality diets which are low in fruits and vegetables but high in fat and sugar. Increasingly, modified diets are being used to treat behavioural and mood disorders such as attention deficit disorder, where diets low in sugar and high in fatty acids are recommended. Children have less control over their food choice than adults as they are highly influenced by their parents. However, children do have a reputation for knowing what they want to eat and being “picky” eaters, and high levels of anxiety have been shown to increase selective or fussy behaviour. Dietary choice, whether it is quality/composition or quantity, is also affected in overweight adults who report increased calorie intake when they are under stress. Stress can interact with eating behaviour in a number of ways regardless of an individual’s normal eating habits.
Nutrition and anxiety can have both independent and interactive negative impacts on health. The life stage at which either of these factors becomes unbalanced impacts on the severity of the outcome. Consequently, insults which occur during critical sensitive stages in development, especially in utero or in early life may have long-lasting consequences. This emphasises the importance of maternal diet and diet during adult life, and their interaction with mental health. The aim of this review is to bring together existing knowledge of how food components affect anxiety at various stages of development, while highlighting some major gaps in our current understanding.