So, you know you need to drop some pounds. You’ve put the tub of protein powder out by the blender and your chocolate stash under lock and key. You’ve bought a membership to your local hot yoga joint. You’re sweating and starving…and the scale doesn’t budge. It’s maddening. Why is it hard to lose weight? You ask the question every time you pass by a mirror or forego a favorite indulgence.

At some point, you think, it should be about simple math: calories burned have to exceed calories taken in. But the solution isn’t as simple as maxing out your Fitbit while eating like a bird. There are a lot of factors that go into losing weight, and they’re not all based on willpower.

Why is it hard to lose weight? Some of the more obvious answers might include:

  • Your mindset.

We all know that crash diets don’t work — at least not for the long-term. And “long-term” is how you should think of weight loss.

It’s easy to obsess over looking trim and fitting into your favorite clothes. It takes more discipline, however, to focus on your health, especially when it’s not always visible.

  • Your diet.

High-sugar, high-fat, processed foods are the curse of the American diet.

If you are used to eating on the fly or reaching for what emotionally feels good, you are doing more than packing on pounds. You are actually starving your body of the nutrients it needs to function properly. That’s why a person who is overweight can also be severely malnourished.

  • Your activity level.

Exercise is an important component to the weight-loss process. But forcing yourself to do something you dread will only lead to a return to a sedentary life.

Exercise, like nutrition, is a long-term commitment, not a short-term fix. Your body was created to move. Find activities you enjoy and do them. A lot.

Maintaining lean muscle is also important, so find an enjoyable way to incorporate resistance work into your workouts.

  • Your stress level.

When you’re doing everything right but are still asking, “Why is it hard to lose weight?” you may need to take an honest look at the stress in your life.

Not only does stress lead to the release of fat-storing hormones like cortisol, it also reduces your willpower to resist high-calorie, high-fat foods. It may also give you an excuse to “chill out” with a glass or two of wine at the end of a tough day.

  • Your age.

Metabolism slows 2-8% every decade. This is one reason that incorporating weight training into your workout routine is so important as you age. Lean muscle keeps your metabolism fired up.

Other factors include health issues, medications, genetics, thyroid issues, skipping breakfast, eating too close to bedtime and not getting enough sleep.

But why is it hard to lose weight on a deeper, systemic level that you don’t actually see and can’t directly control?

The answer lies in metabolic dysfunction and a vicious cycle that goes from bad to worse if you don’t take aggressive steps to stop it.

Most overweight people feel hungry because they have a metabolic problem that includes no satiety signal. They are often insulin resistant, meaning that their muscle cells have closed their doors to the sugar that insulin is trying to clear from the blood.

Instead of pushing the sugars into the muscle cells to be used as fuel, insulin has to detour and deposit those calories into fat cells. Meanwhile, the pancreas has pumped out even more insulin to try to clear the elevated blood sugars.

Keep in mind, the body needs nutrients in order to function. And no matter how much “poison” you put into it, it still needs specific, clean nutrients to accomplish its tasks. That goes for burning fat, as well. You may eat in response to cravings, but your body will still be hungry for what it needs.

Once insulin resistance sets in, a host of dangerous problems aren’t far behind. This is how metabolic syndrome and pre-diabetes begin.

Fat continues to build up, especially around the belly. The pancreas and liver get fatter, and the cycle intensifies. Because the liver is responsible for breaking down fat, anything that disrupts its healthy functioning also disrupts fat metabolism.

The important thing to remember when asking, “Why is it hard to lose weight?” is that everything is connected. None of these processes and risk factors exists in isolation. And neither do your choices.

By choosing to intervene on behalf of your health with a medically guided program of nutrition, exercise and support, you can do more than just lose weight. You can give your body what it needs to sustain you for a long, healthy life.