You are not alone, feeling unusually chilly, especially your hands and feet, is very common during weight loss. And, unsurprisingly, it’s a super common topic of conversation for those of us on Mounjaro or Wegovy, so don’t worry.
Some reasons why you feel colder…
You’re losing natural insulation: Body fat, specifically the subcutaneous fat right under your skin, acts like a built-in blanket that traps heat and protects you from cold environments. As you lose this fat you simply have less padding to keep the warmth in which, of course, can make you feel cold sooner than you used to.
Your internal boiler has turned down: When you digest food, your body generates heat in a process called diet-induced thermogenesis. Because you are eating fewer calories, your body is producing less of this digestive heat.
I wore hoodies all through spring and summer!! Even when my friends were in t-shirts – Ben
Your metabolism is adapting: When you are in a calorie deficit, your body tries to conserve fuel by slowing down your metabolic rate. This “energy-saving mode” means your body produces less heat overall. This can leave you feeling colder, especially when you aren’t moving.
I experienced coldness the whole first week on the jab – Katie
You might have nutrient gaps: Eating less can sometimes make it harder to get all your essential nutrients. These include iron, vitamin B12 and B9. Deficiencies in these areas can impact your red blood cells and oxygen delivery. This makes it harder for your body to regulate its temperature.
And that’s not the end of it. If you’re using GLP-1 weight loss treatments there’s a few extra reasons you might be colder than normal:
Brain & brown fat communication: GLP-1 medications interact with the hypothalamus, the part of your brain that controls both appetite and core body temperature. Research suggests these medications might stimulate your “brown fat” (a type of fat that generates heat) in the same way your body reacts to cold water exposure, essentially altering how you regulate your internal temperature.
Shifts in Blood Flow: These medications can lower blood pressure, which is great for your heart, but it means your body might send less blood to your extremities. Your body prioritizes keeping your vital core organs warm, which is why your hands, feet and nose might feel freezing.
Tips to warm up
The good news is that this cold sensitivity is usually temporary and improves as your body adapts to its new weight. Until then, here are some easy ways to stay cozy:
- Eat plenty of protein: Protein has a higher thermic effect than carbs or fats. This means your body burns more calories (and creates more heat!) just by digesting it.
- Keep moving: Light movement like stretching, walking and even household chores boosts your blood circulation and generates body heat.
My job is desk based and I regularly get up to move about…otherwise I get really cold – Trevor
- Layer up smartly: Wear thermal socks and dress in layers using insulated fabrics like wool or fleece to trap heat close to your body.
- Sip warm fluids: Drinking hot tea, coffee or warm lemon water throughout the day can gently raise your core temperature.
- Don’t undereat and fill your nutrient gaps: Make sure you are eating enough to support your body. Extreme calorie restriction can backfire by slowing your metabolism too much and worsening your fatigue and cold sensitivity.
Watch out and be aware
While feeling cold is usually just an annoying side effect, it can occasionally point to an underlying issue like an underactive thyroid (hypothyroidism) or anemia. If the cold is extreme, gets worse over time or is paired with other issues make sure you check in with your doctor or healthcare provider.
Want to know more about side effects and how to manage them? Take a look at this article about feeling cold, other side effects and nutrition.
