You’ve cleaned up your diet, you try to exercise on most days, and even though you may have lost some weight, those last few pounds just won’t seem to budge. What’s up with that?

Here are a few things that can affect your weight loss that you may not have thought about:

1. You’re sleep-deprived.
According to a Gallup poll, 40 percent of people get less than 7 hours of sleep each night. Without enough rest, the stress hormone cortisol (as well as blood sugar and insulin) all rise, which can make you feel hungry and shut down your ability to use body fat for fuel. Under-sleeping also causes insulin resistance, which not only keeps the pounds packed on, but also leads to Type 2 Diabetes.

2. You’re too stressed out.
A recent study found that women gain 11 pounds a year when they’re under stress. Stress raises cortisol production (which breaks down muscle and lowers serotonin), so you store fat and crave more sweet foods. Because high cortisol lowers stomach acid production, your digestion is compromised too.

3. You eat too much at night.
Total calories eaten DO matter, but if you undereat during the day and stuff 75% of your calories into your body right before bedtime, you are completing the recipe for storing fat. Eat often enough during the day, eat a protein source every time you eat, and limit your evening meal to the smallest portion of the day. You should eat to fuel what you’re going to do for the next four hours.

4. You use a hard workout as an excuse to eat.
Just because you burned a bunch of calories at the gym doesn’t mean you have a free pass to eat whatever you want. Also, watch out for the trap of eating something you shouldn’t, with the intention of “burning it off later.” It’s easy for your body to store fat, but it’s not as easy to coax it to give up the stored fat during exercise! Your body is constantly using stored fat for fuel. The key to long-term weight control is not to put it back on again.

5. You’re eating too much sugar without realizing it.
Blatant sugar overload isn’t the only problem, it’s the sneaky sugars in so-called “healthy” smoothies, yogurt, and low-calorie foods that can wreak havoc on your waistline. Fructose (fruit juice and high-fructose corn syrup) is the worst, because excess fructose goes straight to the liver where it’s turned into fat (see Chapter 3 of Beating Sugar Addiction For Dummies). Fructose overload also triggers your sweet tooth, so you want more and more even though you’re not hungry anymore. Read nutrition labels, and avoid overdosing yourself with fruit drinks and sugary coffees.

6. Your thyroid is underperforming.
Thyroid function is important for metabolism, and an under-active thyroid is one of the most common problems that can get in the way of weight loss. Chronic stress and poor nutrition are guaranteed ways to whack your thyroid. Your defense? Eat right, get enough sleep, practice some stress management techniques, and take a good multi-vitamin/mineral supplement with a B-complex built in.

7. Your body is “toxic”.
Pesticides, pollution, plastic residues, pharmaceutical runoff, and other environmental toxins can disrupt your hormones, lower your metabolism, and make you unwell in general. You can’t completely eliminate exposure, but eating organic foods and avoiding as many environmental chemicals as possible are good practices for you and your family.

8. You yo-yo diet.
If you’re consistently going on and off the latest diet crazes, you’ll never have long-term success. In order to maintain a healthy weight, you have to make non-foolish eating normal. If you go on a special diet, you’ll probably lose some weight. Then you go “off” it, and go back to how you were eating before. But that’s how you got fat in the first place, remember? You haven’t changed anything. In order to keep your weight under control, you have to change what is normal for you ­– what you do most of the time.