Causes
Why It’s Hard to Lose Weight — and Keep It Off
If you’ve tried to lose weight, you already know it’s not just about “willpower.” There are strong biological and environmental reasons why weight loss — and especially maintaining it long term — can be difficult:
1
Your body tries to protect its weight
When you lose weight, your body thinks it’s “starving.” It slows down your metabolism, burns fewer calories, and increases hunger hormones to encourage you to eat more.
2
Hunger increases, fullness decreases
After weight loss, hormones that make you feel hungry rise, while those that make you feel full drop. This effect can last for months or even years.
3
Food is everywhere
High-calorie foods are easy to find, often cheaper, and heavily advertised. Staying on track can be challenging when tempting options are all around you.
4
Old habits are hard to change
Eating patterns and lifestyle routines built over years can be difficult to adjust, especially when life gets stressful or busy.
5
Medical conditions and medications can play a role
Hormonal disorders (like PCOS or thyroid problems), poor sleep, stress, and some medications (such as certain antidepressants) can make it harder to lose weight.
Risk of Weight Gain With Psychotropic Medications
Risk Level
Antipsychotic
LOW
Aripiprazole; Brexpiprazole; Cariprazine; Lurasidone; Ziprasidone
INTERMEDIATE
Amisulpride; Quetiapine; Risperidone
HIGH
Clozapine; Olanzapine
Risk Level
Antipsychotic
LOW
Moclobemide; Vortioxetine; Tranylcypromine; Venlafaxine; Desvenlafaxine; Fluoxetine; Imipramine
INTERMEDIATE
Escitalopram; Sertraline; Duloxetine
HIGH
Amitriptyline; Citalopram; Mirtazapine; Nortriptyline; Paroxetine; Phenelzine
1
Review
Consider the risks of weight gain associated with psychotropic medications
2
Minimise
Consider switching to a weight-neutral or low-risk agent; avoid using multiple agents where possible
3
Manage
Encourage patients to undertake healthy eating and physical activity long-term
