A depression brings a number of effects and symptoms. An influence on weight can be one, or weight gain. But is it not also possible that weight loss leads to depression? Finally, what is the link between eating disorders and depression?
Let us try to take stock.
Causes of unintended and uncontrolled weight loss
This is a weight loss that is not the result of dieting or anorexia nervosa and weight loss of about 10-15% of the original weight.
Dietary causes (changes in diet, malnutrition)
Psychological causes (significant stress, depression resulting from traumatic shock, isolation)
Drugs, alcohol, tobacco
Infections or diseases (metabolic, neurological, cancer or chronic diseases).
Good to know: Depression can sometimes coexist with a physical illness.
Weight loss as a symptom of depression
The diagnosis of depression is made through a series of symptoms: practitioners look for persistent signs that can signal depression. Weight loss is one of those signs. Indeed, the depressed person, losing all interest in food, any pleasure relationship to make to eat or eat, can begin to lose weight.
Thus, weight loss is related to depression in particular by an appetite disorder induced by the lack of interest that is often recognized in depressed people. Sometimes these people do not realize the fact that they are never hungry and do not eat.
Good to know: the reverse is also true: depression can create a need to fill a void and therefore an important food intake, leading to weight gain.
Relationship between depression and anorexia nervosa
We talk about mental anorexia for people controlling their dietary intake in order to induce weight loss to reconcile a fantasy image of their body.
This eating disorder can be caused by psychological causes, such as depression, but it is not yet clear whether anorexia leads to depression or vice versa. In any case, it is clear that self-esteem and perfectionism can be linked to depression. These are characteristics related to eating disorders.
Good to know: it is the same for bulimia. This eating disorder does not necessarily cause weight loss, but it can be seen that a pre-existing depressive state may be responsible for this.
Influence of weight loss on depression
The University College of London has shown in a study published in 2014 that overweight people who have lost weight are 52% more likely to be depressed than those who have not lost weight.
They linked this conclusion to the fact that the hopes and the efforts put into the weight loss are often disappointed: if indeed the health is much better, the problems existing elsewhere (family, emotional ...) are found there Not miraculously settled. Hence a difficult life transition after a period of trying regime. Transition that all do not operate successfully and that can bring a depressed mood more easily.
Other studies have also shown that obese people were at greater risk for depression (Clinical Psychology: Science & Practice, 2008).
In case of nutritional deficiencies
Attention also to the various nutritional deficiencies that one may encounter. Whether it is following a dieting or more simply following a bad diet.
They will not systematically lead to weight loss but, on the other hand, they can lead to depression, combined with other factors (Journal Natural Clinical Nutrition, 2013 - Encyclopedia of Natural Medicine):
- B vitamin deficiency
- Vitamin D deficiency
- Omega-3 fatty acid deficiency
- Nutrient and mineral deficiencies: zinc, folate, chromium, iron, iodine ...
- Deficiency in amino acids and in particular in tryptophan, precursor of the serotonin involved in the regulation of the mood.
Note: iodine contributes to the proper functioning of the thyroid. Hypothyroidism can lead to depression, but it is not caused by iodine deficiency resulting from poor dietary intake.
Two-way relationship between depression and weight loss
Thus, there is a link between depression and weight loss, but it seems ultimately to be two-way: if depression often causes an effect on appetite and therefore weight loss (psychological problems are responsible for about 15 % Of the weight loss encountered in the clinic), it is not ruled out that weight loss, or its causes, can lead to depression.
Moreover, if they are not yet clearly explained, depression is also related to the eating disorders of anorexia and bulimia. These can also lead to weight loss.