NEAT is an acronym that stands for Non-Exercise Activity Thermogenesis, which is just a fancy way of saying all of the calories you burn outside of exercise, eating and sleeping.
Your daily caloric expenditure is composed of three things:
1. Basal Metabolic Rate which is the number of calories you burn as your body performs basic (basal) life-sustaining function. Basically what this means is it is the amount of calories you would use if you stayed in bed all day and didn't do anything.
2. Thermic effect of food which is the increase in metabolic rate (the rate at which your body burns calories) that occurs after ingestion of food. Your body has to expend energy to digest and store the food you eat so this is a measure of that.
3.Activity Thermogenesis which is everything else. Most activity thermogenesis is not exercise based but actually occurs as we go about our day doing our daily tasks. This is the area that you need to increase calories burned if you want to lose weight, and this is where NEAT becomes a major factor.
NEAT varies by up to 2000 kcal/day between people of similar size because of the substantial variation in the amount of activity they perform. Obesity is associated with a low NEAT, obese individuals stand and ambulate for 2 & 1/2 hrs a day less than lean sedentary individuals. The law of conservation of energy states that body fat increases when energy intake is consistently greater than energy expenditure. Excess body fat and obesity are the result of a sustained positive energy balance, which means that a person is consuming more calories than they are burning. Increasing the amount of NEAT in a day is an important part of increasing energy expenditure and achieving weight loss.
What does this mean to the average individual? Basically it means that you have to move more during the day to lose weight. Any activity counts. It can be as simple as going grocery shopping, cleaning the house or doing a little yardwork. Take any opportunity to move that you can.
I feel that the pandemic and our new work from home culture has added to the obesity epidemic because it decreased a lot of the movement that people got by walking to and from their car to the office, walking around the office, and doing their own grocery shopping. This is particularly evident in people who live in small apartments. For example, when I go to do laundry I have to walk upstairs, collect laundry from 4 different bedroom hampers, sort it, walk back downstairs with the first load, walk back upstairs to get the additional items that other family members tell me urgently need to be washed, run the wash, sort the wash into things that need to be hung out on the line and things that need to go in the dryer, walk to the backyard and hang out line dry stuff, walk back out to the backyard to collect it, fold it all and return the piles to everyone's room. Contrast that energy expenditure with a person who lives in an apartment who only needs to walk 25 steps to the washing machine and you will see why it has become harder for people to keep weight off during the pandemic.
If you are in a situation where you don't expend a lot of energy during the day you need to make an effort to increase your NEAT any way that you can. This may include pacing while on the phone, going for a quick 5 minute walk several times a day or even vacuuming. These little activities can add up to a substantial calorie burn outside of exercise!
Levine JA, Vander Weg MW, Hill JO, Klesges RC. Non-exercise activity thermogenesis: the crouching tiger hidden dragon of societal weight gain. Arterioscler Thromb Vasc Biol. 2006 Apr;26(4):729-36. doi: 10.1161/01.ATV.0000205848.83210.73. Epub 2006 Jan 26. PMID: 16439708.
Levine JA. Non-exercise activity thermogenesis (NEAT). Nutr Rev. 2004 Jul;62(7 Pt 2):S82-97. doi: 10.1111/j.1753-4887.2004.tb00094.x. PMID: 15387473.undefined
Levine JA. Nonexercise activity thermogenesis--liberating the life-force. J Intern Med. 2007 Sep;262(3):273-87. doi: 10.1111/j.1365-2796.2007.01842.x. PMID: 17697152.undefined
Picture and graph from this article: Levine JA. Nonexercise activity thermogenesis (NEAT): environment and biology. Am J Physiol Endocrinol Metab. 2004 May;286(5):E675-85. doi: 10.1152/ajpendo.00562.2003. Erratum in: Am J Physiol Endocrinol Metab. 2005 Jan;288(1):E285. PMID: 15102614.