Instead of attempting a modification of your
metabolism to achieve a desired weight gain or weight loss goal, the recommended and more effective approach is to adapt your caloric intake and / or your level of physical activity to attain the caloric balance that will allow you to achieve your goal (you can read more about this topic here:
Slow metabolism - Is it to
blame for weight gain?).
If you have no idea how many calories and in what amounts you've consumed per day, it's easy to
blame skipping breakfast, your genes,
slow metabolism, the society or your neighbor's cat.