Over-eating
In one sense, we eat too much. We eat so much food that people are more likely to get sick from issues related to over-eating than under-eating. In the 2017-2018 financial year, the Australian Bureau of Statistics released a report finding 67% of adults were overweight or obese, a figure likely greater today than when the report was released.
Yet, in another sense, we do not eat enough. Or rather, we will never be able to eat enough because what we really want is not something we will ever be able to obtain through food.

Josef Pieper in his magisterial work Happiness & Contemplation says humanity is always ‘thirsting’ for something more, but we are often drinking from the wrong cup. To take this back to eating, people over-eat because they are quite certainly trying to fulfil themselves, they are just eating from the wrong dish.
Rather than a large Big Mac Meal, perhaps what they want instead is a large hug with a side of friendly compassion. Rather than a HSP, perhaps what they want instead is a main course of parental affection with non-critical love for desert.
Humanity, writes Josef Pieper, thirsts for happiness, but seeks it in the wrong places out of ignorance. We seek it in fame, glory, riches (or food), only to find these fleeting vapours ephemeral and insubstantial. Because we cannot properly locate the source of our under-nourishment, we seek it elsewhere.
Taken from this angle, the question of why we eat too much is intimately connected to the question of why we drink too much, smoke too much, or have sex too much.
We are seeking to quench a thirst that is spiritual, but which we incorrectly identify as physical. We want to be fulfilled, deeply, personally, spiritually, and not knowing how, or not knowing that we even want to, we try satiating this spiritual thirst with material things. We are, as Pieper would say, drinking from the wrong cup.
What we really want is some friends (or maybe only one) in whom we can confide and who will allow us to be our fractured, messy selves. What we really want are parents who will love us unconditionally, despite (or in spite of) our flaws. What we really want is a life where we can have meaning, purpose and direction. But, we do not often pay attention to what we really want. The thing is, just because we aren’t paying attention to what we really want, does not mean it goes away. You can ignore your thirst, but it won’t stop you being thirsty, or at least, not for long.
In a weird way, we over-eat, over-drink, and over-smoke, not because we are greedy, but because we are starved. Starved of the necessary spiritual nourishment that would make us feel fulfilled. We should look more kindly on those who overeat (and over-drink, over-smoke, and so forth), understanding that their behaviour is a symptom of a deeper emptiness that they are trying to fill the only way they know how. They don’t need another Big Mac, what they might need is someone to care for them, listen, and help them find meaning in life, and you might be just the person to do it.