Can you hold on to excess fat by not eating enough calories

    No. Any time you are consuming fewer calories than you burn, you will lose (and continue to lose) weight comprising of lean body mass (LBM) and/or fat until your calorie intake matches or exceeds your calorie expenditure. Those are the facts. The goal is to lose only body fat (unless you are extremely overweight in which case you will lose some LBM). This is accomplished by not going too low in your calorie intake, safeguarding that your muscles have enough nourishment to maintain their size and workload during the weight-loss program.

To put the issue into viewpoint, first realize that children and adults around the world who die of starvation are not fat when they pass away.

    To be sure, when you severely cut calories, your metabolism will make a slight change (not a large compensation), allowing it to run on fewer calories. This is where some health professionals get confused about "holding onto fat."

  The real problem is that as you lose weight, it gets harder to continue progress because you are lighter and fit. Your amplified efficiency forces you to have to perform more work or eat less in order to continue progress. So don’t worry about the slight decrease in metabolism, simply keep your workout "unaccustomed" or add movement (e.g. steps) to your daily activities as your weight decreases. Also often when dieting on extremely low calorie intakes, you may be slowing down. In other words, you become less energetic, forcing a decline in your daily activities and therefore burning fewer calories overall. This can lead to a weight-loss plateau.

So the answer is no.