Healthy diet or balanced nutrition depends on emotions. According to Macht, Roth and Ellgrin(as cited in Macht, 2007), happiness and other positive emotions increase our level of eating and consumption of healthy food. Sadnes and other negative emotions decrease our level of eating. When people are sad, they prefer to eat unhealthy food and they prefer to eat  outside because when they eat outside or eat fast food, they feel better. Lyman(1982) found that we consume healthy food  when we have positive emotion but we consume junk food when we have negative emotions.

    Most  researchers have been interested in different emotions and their effect. Mehrabian(1980) was interested in relationship between emotion and level of eating. He wanted to imagine themselves in emotional states and then asked how much they would eat in emotional states and he reported the results. He found that when people are in boredom, depression and fatigue, they consume more food. However, when people are in fear, tension and pain, they consume less food(as cited in Canetti, Bachar & Berry, 2002). Emotions affect our amount of food intake so it may lead to eatind disorders. Generally, eating disorders emerge in both negative emotion and negative cognition(Fox & Power,2009). Some researchers analyzed different effects of some emotions such as anger, fear, sadness and joy. Macht(1999) was interested in this subject and he reported that when people are happy, their level of hunger is higher than level of hunger in fear and sadness and he found that when people are angry, this emotional state impulse their eating such as fast, irregular and careless eating. On the other and, being cheerful during dinner completely satisfies taste of the food(as cited in Canetti et al. ,2002).

    Some researchers think that food intake is not associated with positive moods but a past study(Patel & Schlundt, 2002) showed that when both positive and negative mood is compared with neutral mood, food intake is larger in positive and negative mood. They also think that positive mood increases amount of eating and this is associated with learning mechanism. For example, happiness is associated with eating more food (as cited in Canetti et al. ,2002).

    Obese people may be affected by emotions about their eating habits. Emotions are more effective on obese people than non-obese people and it is more effective on dieter people than non-dieter people (Canetti et al. , 2002). For instance, negative feelings of obese people are stronger and deeper than non-obese people, so this may cause eat more when they face with bad situation.

                                                        References

Canetti, L.,Bachar, E. & Berry, E. M. (2002). Food and emotion. Behavioral Processes, 60, 157-164.

Fox, J. R. & Power, M. J. (2009). Eating disorders and multi-level models of emotion: an integrated model.Clinical Psychology & Psychoterapy, 16, 240-267.

Macht, M. (1999). Characteristics of eating in anger, fear, sadness and joy. Appetite, 33, 129-139.

Macht, M.(2007). How emotions affect eating: A five-way model. Appetite, 50, 1-11.