The link between diet and exercise and weight loss?

clareyoung80

Not sure if this is the right forum, but I've got a query about exercise and its link to fat loss.

From what I've read about it, it doesn't seem to be a simple correlation between calories in calories out. Exercise seems to have a differing effect to your weight loss over a simple 'calories out' equation.

So, when you're not eating enough to cover your calories burnt, you don't lose weight...or rather, not in the simple mathematical sense. Because your body is holding onto your fat reserves or something. But does it work the other way round? If you eat 2000 calories a day and burn 800 calories through exercise...do you lose weight? Or are you exercising too much? Or are you still eating too much?

Obviously the specific numbers depend on the person... and yeah, exercise is great great etc, but the more I read the more I'm starting to think exercise is a separate thing in terms of weight loss. Or rather, I'm tempted to ignore it when it comes to the calorie deficit factor.

Or I'm just really confused... any thoughts that could clear my head?

Cherry_T

That`s correct. Exercise serves both a direct(burnt calories) and passive(boost metabolism, grow muscle, etc.) purpose. The passive is more important and lasting.

AJ_G

It is a direct link between the net calories for the day. That being said, increasing muscle mass through strength training will lead to an increase in maintenance calories to sustain that muscle.

grimendale

It is calories in/calories out. What exercise affects, and what the size of deficit affects, is the source of those calories. When you eat at a deficit, your body burns both fat and lean body tissue. When the deficit is fairly small, the majority of the calories burned are going to be fat, particularly if exercise is involved to convince your body that the muscle tissue is necessary. As the deficit increases, the ratio begins to shift towards burning mostly lean body tissue. This is because muscle cells require more calories to maintain that fat cells, so it is more efficient for making up a large deficit. If the defiict is large enough and continues for long enough, the ratio shifts to primarily muscle tissue to preserve as much fuel for future use as possible. If this continues long enough (typically over the course of many weeks), the metabolic rate of the body can be damaged. If your deficit is too large, you will still lose weight, but much of that weight will be muscle tissue rather than fat. A small deficit combined with resistance training is the best way to ensure that most of the calories burned are fat rather than muscle.