I've had clients ask if spot reducing is possible because they like their bodies except for the fat thighs or the fat butt. In my own case, there is seems to be a small, fat pouch right at my waistline that I'd love to lose (my husband says I'm crazy, but I can see it!) There are a hundred new articles and reports daily in the news about weight loss and, of those, there is an equal chance of the information being fact or fiction. There are no miracles in weight loss, though there are lots of myths. You may have heard the new one making the rounds: cortisol will 'dissolve' fat around the waist. Fiction.
Whenever you take in more calories than you use, the remaining energy is stored in chemical bonds between adipose tissue (fatty deposits). In adult men those fat deposits are preferentially stored around the waist and abdomen, in women around the hips, thighs and abdomen. Spot reducing would be a great thing if it were possible, but in truth, the fat usually seems to come off last where it last went on.
As you take actions that place a demand for energy on your body that is greater than can be supplied by available glucose (its preferred source), it turns to fat to supply the deficit. Fat molecules are broken down and severing those chemical bonds releases the energy needed for maintaining internal temperature, muscle movement, etc. Be careful though, not to overdo cardivascular exercise as after a point, your body will start to break down muscle tissue to use for energy. The loss of muscle tissue is counter-productive to fat loss as muscle will burn fat even at rest. Muscle also adds attractive definition to your body.
But, here's the rub about spot reducing: you have no control over where the body takes that fat from. Cortisol may aid in releasing those fat deposits and breaking down those bonds, but it isn't targeted. There is, currently, no spot reducing technology that will remove local fat deposits from any part of the body except mechanical removal, such as in liposuction.
It's true that doing abdominal exercises, though, helps reduce fat around the waist, and in two ways.
First, since abdominal exercises typically involve large-scale movement that requires high effort, it naturally requires lots of energy. Once the available free energy is consumed, the body turns to those fat deposits to get more. The result is less fat and weight loss.
But it does that in an overall way, with no narrow location getting most of the benefit. Most of the fat may indeed come from the waist, but that's because that's where most of it is, as a percentage. But the exercise doesn't target that fat in any way. This isn't really spot reducing.
Second, during a vigorous abdominal workout those muscles are being worked harder than others. That's the whole point of abdominal exercises. As a result, those muscles (along with the back muscles, typically) are being strengthened. Toning and strengthening those muscles helps restore their youthful ability to hold in the internal organs, primarily the stomach.
Other exercises that utilize the larger muscles of the body and many stabilizer muscles, such as squats and lunges, have the same fat-burning effect as abdominal exercises.
At the same time there will be a (largely temporary) loss of fluid that contributes to both weight loss and slimming. The net effect is that the waist looks slimmer, the bulge is reduced. That's definitely a good thing, both for general health and weight loss or fat reduction.
But it's not the same thing as targeting specific fatty deposits, as the makers of cortisol pills (and other) 'miracle cures' would like to sell you. The only effective program for reducing fat deposits - around the waist, on the thighs and buttocks, or anywhere else - is the old-fashioned, high effort, high willpower one.
A program of adequate daily exercise and proper diet is the key to long-term health, safe weight loss and fat reduction. You'll feel better and your health will be optimized. And, even though you aren't spot reducing, you'll reduce those unattractive fat deposits around the middle.
Spot reducing might be a myth, but a good exercise and nutrition plan can do the job.