Definition of RMR, TDEE, TEF, TEA, NEAT

TDEE total daily energy expenditure (TDEE, the number of calories burned in a 24-hour span) is made up of 4 factors: RMR, TEF, TEA and NEAT. And all four can go up for several potential reasons when calories are increased or weight is gained.
It is the higher number located on page 3 of your report.

RMR is resting metabolic rate and represents the number of calories burned by the body at rest and may make up 60-75% of TDEE. It is primarily impacted by the amount of lean body mass although other factors such as hormones play a role here. RMR will go up a total body weight and muscle mass goes up although the resting calorie burn of muscle is actually quite low (about 6 cal/lb). To gain 10 lbs of muscle and you might burn 60 calories more at rest. Hooray. More contentions is whether there is an increase in RMR above what would be predicted for bodyweight and for the most part, it either doesn’t occur, is fairly insignificant or is very short-term (in one study, it went up by about 100 calories in the first 2 weeks of 8 total of big-time overfeeding).

TEF is the thermic effect of food, the number of calories burned in the processing of food. This is typically taken as 10% of total calorie intake (this might go to 15% if protein intake is particularly high) and increased food intake will mean a higher TEF. Thing is, it’s pretty insignificant. At 1000 calories above maintenance, TEF goes up by maybe 100 calories. But it does contribute to all of this.

TEA is the thermic effect of activity, the calories burned during formal exercise. TEA can vary enormously from zero calories per day (no formal exercise), up to hundreds or thousands of calories per day (endurance athletes may burn 1000+ calories in a long workout). This too goes up with weight gain. A heavier body will burn more calories during exercise so that will also go up. Since TEA is a conscious thing, whether or not the total amount of exercise goes up depends on the person. There may also be changes in muscular efficiency here which would impact on the number of calories burned. Frequently people both train more and more intensely when they are eating more and this would mean a higher calorie burn.

NEAT which is non-exercise activity thermogenesis. Originally this referred to unconscious movements that burned calories but now includes any activities which aren’t formal exercise (I.e. gardening, walking from the car to the store). NEAT is the most variable of all the components and two people can have NEAT that varies 2000 calories per day from highest to lowest. This tends to be dependent on lifestyle and environment.

RMR should be your caloric foundation and the minimum calories you should be consuming. It is recommended to eat more than this if you are active and want to maintain lean muscle. If your Doctor or Dietitian has you on a weight loss plan at a lower number then we recommend you consult with your doctor and follow their prescribed recommendations.