First off I want to start off by saying the only way to lose weight is by being in a calorie deficit.
What does this mean?
That means that the number of calories you consume needs to be less than the number of calories you burn in a day. For example:
Let's say you eat 2000 calories in a day. You would have to burn 2001 calories in order to chip away at your weight loss goals. The more drastic the caloric deficit, the more weight you drop in the quickest amount of time.
Personally, I wouldn't suggest severe caloric deficits of greater than 250 calories in order to prevent the misery that come come from dieting.
Losing Weight Doesn't Have To Be Miserable
Consuming less calories is the route most people choose when attempting to lose weight. This method however is usually easier said than done. If you factor in weekend at the cottage, birthdays, holidays, random nights out with friends, it can be very difficult to sustain restrictive eating patterns long term.
The best way to lose weight? A combination of consuming less calories, resistance training & understanding how we burn calories.
I have linked a visual below to allow for better interpretation of how we burn calories.
As you can see, your BMR accounts for the majority of calories burnt in a day, followed next by NEAT, then exercise & finally the thermic effect of meals.
Meaning that increasing your BMR is the most important factor in determining how many calories you burn in a day by a large margin.
How Can I Increase My BMR?
Your BMR - basal metabolic rate - is the rate at which your body requires to basically keep you alive. It is a combination of your height, weight, age, sex, bone density, muscle mass, organs and a few other factors.
Many of the aforementioned you cannot change; the key variable to target here is muscle mass.
Through resistance training, estimates suggest with proper programming, sleep & nutrition, you can put on maximum 1-2lbs of muscle a month depending on genetics and various other factors.
Len Kravitz discusses hIn at least one discussion of caloric expenditure, researchers at the University of New Mexico explain that the change in metabolic rate per pound of muscle tissue has been roughly in the range between 4.5 to 7.0. The researchers estimate that muscle tissue contributes approximately 20% of your total daily calories burned versus 5% for fat tissue (for individuals with about 20% body fat).
Kravitz, Len, Ph. D. Controversies in Metabolism.
University of New Mexico.
How Can I Increase My NEAT?
NEAT: Non Exercise Activity Thermogenesis is the number of calories you burn doing everything from fidgeting to getting up and going to the bathroom.
This accounts for roughly 30% of the overall calories you burn in a day.
In short, MOVE. Walking to work, bending down to tie your shoes, reaching for the last jar of peanut butter on the top shelf, all of these qualify as NEAT.
Next up on the list of most important contributors to energy expenditure, we have Exercise.
This category includes working out. However, it only accounts for roughly 15% of overall energy expenditure. That being said, the more intense your workout, the closer you get to maximizing that full 15% allotted to exercise so use it.
Finally we have the thermic effect of food. Yes, eating burns calories too. However, given how minimal the amount of calories you can burn in this manor is, I highly suggest not depending too much on it to meet your weight loss needs.
In short, a combination of consuming less calories, training hard, adding muscle & moving more is the best way to meet your weight loss goals and ensue the results you achieve are sustainable. Not to mention you'll feel better in copious other areas of life on a daily basis.