> walking or even running for 5 miles each day will not decrease the weight This is so wrong. Humans have come up with calories as a measurement of how the bod

> walking or even running for 5 miles each day will not decrease the weight This is so wrong. Humans have come up with calories as a measurement of how the body burns fuel. Food is the fuel and burning that fuel is spending calories. You can reduce the calories consumed and/or increase movement to burn more. A quick google indicates 1 mile walking is about 100 calories burned for a 180lb person. So walking 5mi is burning roughly 500 calories and if done daily, this would mean 3500 per week which is roughly 1lb of loss. If you replace that 500cal loss per day with 500cal of ice cream then yeah you’re not going to lose weight. So if someone decided to just eat all the same stuff they currently eat but go walk 5mi day they would likely lose weight. Calculating weight loss is mathematically very simple and software devs should be familiar with feedback loops. The simple formula is track calories, weigh yourself, adjust calories for loss, weigh self. Daily tracking works. The LoseIt app does this for you and adjusts calorie budget when you lose weight (less weight means lower budget).