Why Am I Always Cold After Getting Weight Loss Surgery?
If you’ve ever described yourself as “warm-blooded”, you might be wondering why you are always cold after getting weight loss surgery. Anecdotally, this is one of the most common side effects of bariatric surgery. If you have previously always worried about overheating, this change might come as a surprise to you. So, why is it happening?!

A new diet, rapid weight loss, and reduction in overall calories can shock the heck out of your system. In this post, I’ll explain what is happening with your body’s processes to make you feel cold all the time after weight loss surgery. I’ll give you some recommendations for keeping your temperature regulated as your body adjusts to your “new normal”.
What is Happening to My Body?
Our bodies are incredible. All those cells and tissues and biological processes allow us to move, birth other humans, and heal after injuries. Our bodies also have the mammal-defining ability to regulate our core temperature.
This is controlled by the hypothalamus in the brain, which normally does a great job of cooling us when overheated or hanging on to every bit of warmth when confronted with a cold snap.
Weight loss surgery is a huge change, but remember your body is capable of great feats, and it will adapt to this new way of living.
Recovering from weight loss surgery is just one of the incredible things our bodies can do. It is not without side effects, however. Feeling cold after weight loss surgery is one of those effects and is really a sign that your body is working as it should. Other side effects after rapid weight loss might include dry skin, aches and pains, and hair loss (1), which I address in other posts.
Why Do I Feel Cold After Weight Loss Surgery?
Our bodies take the calories we consume and convert them into energy. When we have an excess of calories, this is stored as fat in the adipose tissue underneath the subcutaneous layer of skin. This is our body’s way of protecting us and preparing for times of scarcity.
Having this extra layer of fat is similar to having a built-in winter parka. It gives us additional insulation, protection, and makes us feel warmer. When we have gastric sleeve or other weight loss surgery, our bodies will use this extra layer of fat as energy. Anytime we lose weight rapidly, it will lead to the loss of this insulation.
If you take off a real parka in zero degree weather, you’re going to feel cold – really freakin' cold. The same things happen when we lose our layers of fat, or our built-in parkas; we are going to start feeling cold more easily.
If you lose a significant amount of fat in a short time frame, then you will have fewer fat layers keeping you warm. This is partly why you feel cold after weight loss surgery, even if your environmental temperatures are mild. Some weight loss surgery patients report being cold even during the height of summer!

Another reason for feeling cold is because the rapid loss of body fat slows your metabolism. Our rates of metabolism can affect our body’s ability to regulate temperature, which increases the chance that you will be feeling chilly.
The third reason for feeling cold after weight loss surgery is a lack of iron, or anemia. Technically anemia is a deficiency of hemoglobin, or red blood cells. When you have weight loss surgery, you will be eating fewer calories, which means your body won’t have as many calories to convert to heat.
It also means you might not be getting enough of some minerals or vitamins. Anemia, or the lack of iron, can be a culprit in feeling cold after the weight loss surgery. It is much more common in gastric bypass surgery patients than gastric sleeve or gastric band patients (2) due to the technical differences in the procedures.
Malnutrition is common after weight loss surgery – more often with bypass – which is why it's so important to focus on nutrient-dense foods.
What To Do About It
Cold intolerance can be an annoying side effect of weight loss surgery, but it's not the worst possible side effect, and it can be tolerable. Here are a few tips to help you get thorough this phase of your recovery.
First, consider stocking up on cute hats, socks, or cozy blankets to take the chill off. Dressing in layers is a tried and true remedy so you can accommodate temperature variations wherever you go. Along with layers, you might need to start packing a lightweight pair of gloves as you will feel the heat loss in your fingers and other extremities.
Cardigans and light jackets are life savers! I have a few in the house as well as one or two in the car, just in case I forget and I get chilly when I'm out and about. The weather changes quickly here because we live right on the water, so even if it's sunny out, it can be cold! I've been dealing with temperature regulation issues since my thyroidectomy, so I've got all the tricks up my sleeve. 😉
The next option is to talk with your doctor if you think anemia might be contributing to feeling cold all the time. You can work with your nutritionist to make sure the calories you are getting are true fuel for your new body, and that you are getting enough iron in your diet.
Red meat*, poultry, seafood, leafy greens and legumes are some of the best sources for iron after gastric sleeve surgery. Talk with your doctor and nutritionist, though, to make sure these sources are appropriate for you and in what amounts.
You will also most likely be taking iron supplements on top of food sources. Iron supplements can cause constipation so be sure to read this post about [constipation after weight loss surgery] for my best remedies.
*Be careful with red meat, it's known to cause a back up: here are some constipation remedies!
How Long Does it Take After Gastric Sleeve for My Temperature to Regulate
As you begin noticing changes in your body after gastric sleeve surgery, you might freak out a little bit. Who is this person? Your body is doing the same thing. It has to adjust to a new normal as well. The metabolic processes that have kept you secure and functioning all this time have to switch things up.
If you have been feeling cold all the time after your weight loss surgery, then just be patient with your body. Give it love via cozy blankets, extra layers, and excellent nutrition. Your body will figure out how to adjust and what it needs to do to regulate your body temperature once you are fully healed from the surgery. In most people this process takes 18-24 months.
Throughout your recovery, you will figure out how to adjust to cold intolerance. It might be annoying to be cold all the time, but it’s way less annoying than medical complications from obesity such as diabetes or heart conditions. Be patient with your body and give it thanks for all the amazing things it can do.
Sources:
(1) Silver
(2)Johns Hopkins
