A calorie deficit is literally the only way to burn fat. Your body won’t touch its fat deposits if it’s getting enough energy from the food you eat. Working out has a limited effect on the amount of fat you burn. It’s all about how much you eat. If visible abs are what you’re after, that means dieting so that your body fat percentage gets low enough. The reason we lift while dieting is to preserve the muscle mass. By just dieting you’re going to lose both fat and muscle.

Eating fewer calories is by far the main thing. Under your daily calorie burn. Even most sedentary people burn 1800 calories a day or so.

That can be coupled with exercise that burns calories.

That’s like 90% of it.

Fat is your body’s energy store. When you need energy, your body will consume it from your bloodstream. If there isn’t enough there, it’ll break down fat to create more.

So what consumes energy?

• Moving
• Thinking
• Being alive

The last one is what uses up the most energy and you’re already doing it.

I don’t really care about downvotes, but those of you doing so… you might want to actually look into the research behind it. I picked a couple of random links for it because there’s literally nothing special about any of it, along with an NIH article about brown fat recruitment. The science is solid. It’s not a magic bullet; it’s not a replacement for healthy eating or real exercise; it does work for raw calorie burning and for making your body system more efficient at staying warm through calorie burning long term. That’s what our bodies are made to do. It’s a great calorie balancing supplement with very little actual effort.

Shivering is a great easy way to burn calories, and increase the rate you burn calories later through beige fat recruitment.

This should NOT be used to replace healthy eating or proper exercise, but shivering burns gobs of calories to produce heat, and the brown fat (located mostly in your back around neck and shoulders, used just for producing heat from fat) recruits surrounding white fat and transforms it into beige fat (basically converts normal fat into leaky heat-generating fat) to increase the heat generation, and thus calorie burn, of subsequent shivers.

Here’s some links about it, if you are interested. It may not be actionable in the summer, but if you have a basement floor you can lay on, a tub of cold water, or access to a walk in freezer, you can get a healthy shiver going any time.

https://www.medicaldaily.com/shivering-more-effective-exercise-15-minutes-shivering-may-burn-more-fat-1-hour-working-out-268555

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8341719/

https://www.discovermagazine.com/health/shiver-yourself-thin-can-being-cold-help-you-lose-weight