You've finally done it: You've lost those 10, 20, 50, or more pounds that you've always dreamed of shedding. You feel better, healthier and more self-confident. Your risk for a myriad of diseases — from diabetes to heart disease to certain cancers — has decreased and you're making changes in all aspects of your life. But you may also be dealing with some side effects of your weight loss that you hadn't expected.

Here's what may be going on inside your body — and in your head — when you lose weight.

Person who is cold When you lose weight, you lose that layer of insulation that once kept your body warm. (Photo: Pop Paul-Catalin/Shutterstock)

You may be cold all of the time. "Sweaters became (and still are) my best friends," says Kate Chapman, a health coach and inspirational speaker who lost more than 100 pounds more than 10 years ago. When you lose weight, you literally lose the insulating fat that blanketed your body and kept you warm. So it makes sense that you will be more sensitive to cooler temperatures. But if your sensitivity to cold is also accompanied by grumpiness, brittle nails, and/or frequent headaches, it might be worth talking to your doctor to make sure your current diet is not leaving you with nutritional deficiencies (like anemia) that are causing your symptoms.

The weight may come off unevenly. Wedding officiant Liz Grimes was eager to lose weight so she would feel better about herself and look better in her clients' wedding photos. But one thing she didn't expect when she lost 80 pounds in 22 months was how the weight seemed to come off in different parts of her body throughout her journey rather than a little bit from each area over time. While she says she has more or less "evened out" now, she was still surprised at the amount of weight she lost overall in her feet. "I was shocked when my shoes became too large!" Grimes told MNN.

Your hormones may be out-of-whack. "Many hormones in the body are based on body weight in relation to the amounts produced," says Danielle Girdano, a certified nutritionist and personal trainer who also lost over 200 pounds. "Many women do not expect that mood or menstrual cycles can change based on these varying amounts, but it happens," notes Girdano. In a study published in the Journal of Oncology, researchers found that extra body fat was linked with increased levels of estrogen and other hormones. The study found that these hormone levels dropped significantly as obese and overweight women lost weight. According to Girdano, that could result in changes to the menstrual cycle that include a heavier or lighter flow or the cycle shortening or lengthening.

Your skin will sag. You probably know that when you lose weight, your skin won't just snap back into shape. But many people who have lost significant amounts of weight are unprepared by the amount of sagging skin left hiding under their clothes. "This is a key emotional component because what a person may think is the right body image may not be exactly what they end up with," Girdano told us. "Being comfortable in who you are, in your own skin is absolutely something that should be addressed."

Sad restaurant plate The diet options at many restaurants may not be as satisfying or as delicious as the full-calorie fare. (Photo: All kind of people/Shutterstock)

Dining out may not feel as fun. Whether you're counting calories, adding up points, or simply trying to fill your plate with lean meats and fresh vegetables, there's no getting around the fact that it can be difficult to eat out when you're trying to lose weight or maintain weight loss. It can be a drag to ask servers about ingredient lists or how dishes are prepared. And as Chapman puts it, restaurant choices may simply become less appealing because your "much more sensitive to the amount of fat, salt, and sugar in foods, and most restaurants have foods loaded with all three."

You may feel angry. It's no secret that when you're overweight, you are treated differently by society. At worst, you may be taunted or harassed, at best you may be ignored. In a groundbreaking 1984 study published in the Journal of Employment Counseling, researchers found that when employers had to choose between equally-qualified potential candidates, they repeatedly passed over those who were overweight or obese, even when compared with candidates who had a criminal record or documented mental health issues.

While it may be exciting to suddenly be accepted by society, it may also feel infuriating to know that the only thing that has granted you access into this new "cool kids' club" is your smaller pants size. Jasmine Singer, executive director of the nonprofitOur Hen House, had this to say about her 100-pound weight loss over on Mind Body Green:

"There were times, I admit, when I felt like throwing my hat up in the air, Mary Tyler Moore style. Finally, I was something. Except — wait — I had been something before, too! I had been a writer, an activist, an actress. I had loved Patti LuPone, kale chips, nail polish colors that were 'too young' for me. Why didn’t anyone notice? Why didn’t they care? More importantly, why did they care now?"

You may feel exposed. To be overweight is to be overlooked, and never is that more apparent than when you lose weight and are suddenly cast into the societal spotlight. "It's only a theory," Chapman told us, "but I do believe that those of us who have worn fat suits are also people who feel things in a heightened way, thus leading us into those suits. Without my fat layer, I don't have a place to hide," she added.

You will have to face your demons. If food was your go-to source of comfort in times of stress, you may need to find new ways of dealing with your emotions and the underlying issues that were causing your stress in the first place. If you suffered from depression or anxiety before you lost weight, that won't simply disappear as the pounds fall away. As a psychotherapist, it didn't surprise David Ezell to learn that he was self-medicating with food. "Nonetheless, I had to heal those underlying issues before I could lose weight and keep it off," Ezell told us of his 83-pound weight loss.

Getting a good night's sleep The incidence of sleep disturbances decreases drastically with weight loss. (Photo: Victoria 1/Shutterstock)

You will sleep better. Research shows that the incidence of sleep apnea, the condition characterized by the breathing disruptions that interrupt sleep as often as 30 times each hour, is as high as 45 percent for people who are overweight or obese. As you lose weight, your likelihood for experiencing sleep disruptions decreases. That, coupled with the fact that many people who lose weight increase their daily allotment of exercise, and it's no wonder that those who have lost weight report getting more and better quality sleep than ever before. "I’m able to workout harder and longer so by the end of the day, I’m ready to sleep and it’s quality sleep," says Kelly Kepner, a publicist and Weight Watchers ambassador who lost over 100 pounds.

You may have fewer headaches. According to the American Migraine Foundation, obesity raises the risk of having a migraine by around 50 percent. That likelihood increases as obesity increases; people with a BMI (body mass index) greater than 40 have a 275 percent higher risk for having a migraine than their peers who are not obese. Obesity is not a cause of migraines, but it is a risk factor, and it is one that can be controlled with weight loss.

Researchers still aren't clear on the link between weight and migraines, but the current theory suggests that fat cells increase the amount of inflammation in the body and this inflammation can trigger migraines in certain situations. Losing weight decreases the level of inflammation in the body and may consequently reduce the quantity and severity of a person's headaches.

Looking in the mirror after weight loss Many of the people we spoke with did not recognize themselves in the mirror after weight loss as they still expected to see the heavier person they once were. (Photo: Tatyana Dzemileva/Shutterstock)

You may not recognize yourself in the mirror. "I am still surprised when I look in a mirror and am so thin," Wayne Eskridge told MNN. Eskridge, president and CEO of the Fatty Liver Foundation, lost 40 pounds over a period of six months. "My mind's eye doesn't believe I look like this," said Eskridge, adding "my brain continues to see me as a larger person." Many of the people who spoke to us about weight loss echoed this thought that the image they see of themselves in the mirror does not match the image they have of themselves in their heads.

Your self-esteem may sky-rocket. You may think that if you could just lose x number of pounds, you will feel better about yourself and everything in your life will fall into place. To an extent, your self-esteem is likely to increase after weight loss, but not for the reasons you might think. "My massive weight loss has brought me a change in personality, a new level of confidence — not just because I feel better about myself, but, sadly, because the world feels so much better about me. And, quite honestly, I like it. I savor it. And to the extent I can get away with it, I use it," said Singer. For better or for worse, society is kinder to people who are not carrying a load of excess weight. And that kindness — from your boss, your coworkers, your family, and even from strangers — can translate into improved self-esteem.

Your relationships may change. You probably knew that when you lost weight you would need a closet-full of new clothes, but did you also expect to need a life-full of new friends? A few months ago, we told you about a recent study published in the journal Obesity that found people who were trying to lose weight were less likely to receive support from their non-dieting family and friends than they were from online or in-person weight loss support groups. As you lose weight, it's likely that you may change (see the note about self-esteem above,) as will your preferences for entertainment, and that may not sit well with your bar-hopping or brunch-indulging friends. That doesn't mean all of your friendships will fall by the wayside, "but if someone isn’t happy for you when you make a choice that is ultimately better for your health, you should probably distance yourself from that person because that’s not good for your mind, your body or your self," says Caleb Backe, a health and wellness expert for Maple Holistics. .

13 surprising side effects of weight loss
What's really going on in your body (and in your mind) when you lose weight.