For most people who are successful at weight maintenance, burning an additional 150-200 calories per day (in addition to your normal daily exercise expenditure) seems to do the trick, though you may need to experiment a little bit to find out what works for you. But—make sure you do NOT reduce your calorie intake below the maintenance level in order to get out of doing more exercise or to “be safe”. To lower your set point weight, you need to avoid restricting calorie intake below your maintenance level, and rely on additional exercise, if necessary, to keep your weight stable.
Other Metabolic Issues
There is some evidence (coming from research on rats) that regaining lost weight is often associated with a change in the normal ratio of fat and carbohydrates used as fuel during various states of rest and activity. Normally, fat is the predominant source of energy at rest and during very light activity, while glucose becomes predominant when intensity of activity increases to moderate and higher levels.
However, rats who are permitted to return to unrestricted eating after weight loss, and who regain weight, show a significant increase in the use of glucose in relation to fat during rest and light activity. If this transfers to human beings (pretty likely), it could mean that the tendency to regain lost weight could depend not only on how many total calories we eat, but also on what we eat and when we eat it.
If our bodies do shift into fat-preservation mode after weight loss, in order to promote weight regain, we might be able to partially counter this effect with dietary strategies. For example, one effect of being in fat-preservation mode is increased appetite, especially for foods high in carbohydrates. To some extent, at least, a diet that relies on multiple smaller meals and is relatively higher in protein may counteract this increase in appetite (protein and frequent smaller meals are both known to increase satiety), and also promote greater utilization of fat stores for energy. We’re not talking Atkins here—just a diet that involves keeping protein near the top of the recommended range (about 30% of total calories), carbs at about 50%, and fat at around 20%. In addition, a diet that emphasizes carbs and meals that are fairly low on the glycemic index, whole grains, beans, nuts, and other foods that are high in protein would help counteract these effects.