Weight loss followed by weight gain – also known as the yoyo effect – is more common than you might think.

I could not find any accurate statistics for the number of people that lose weight then gain it back. Some studies show it’s as high as 95 percent. Others put it around 85. Whatever it is, I can tell you from the personal experience I have working with individuals through health coaching and specific weight loss programs, it’s a lot. I would guess it is in the upper range of 95 percent.

And the reason for weight regain has more to do with than science than it does with willpower.

Enemy Number One: Adaptive Thermogenesis

Diet-induced weight loss is accompanied by a process called adaptive thermogenesis which is a disproportional or greater than expected reduction of resting metabolic rate. In other words, the body has an uncanny knack for wanting to be at a certain weight and dieting seems to elicit a biological reaction to negative energy balance or caloric reduction. When you eat less to lose weight, your body slows down to prevent you from doing so.

The plateau and weight regain that generally follows this large energy deficit may exceed weight loss so that a net weight gain may be the outcome of such a weight loss cycle.

There are still many unknowns about the dieter’s number one enemy, adaptive thermogenesis. Scientists continue to study this built-in adaptation system to learn more about its relationship to weight loss and the seemingly inevitable weight gain that follows. What they do believe is that a reduction in energy intake (food) results in an equivalent decrease in the resting metabolic rate.

Does This Make Successful Long-Term Weight Loss Hopeless?

The answer is no. While this balancing act that takes place is in the body is somewhat beyond your control there are some things to keep in mind when trying to lose weight and keep it off.

Here are some things you should know:

A slow weight loss program will prompt better long term results than a fast one will. Research shows that an aggressive weight loss program slows down your metabolism more than a moderate one does. We’ve all heard of the starvation mode theory that suggests that if you cut your calories down too low your body will think it’s starving and hang onto body fat. This is the basic principle of adaptive thermogenesis. The more you shock your body with extreme calorie deficits, the harder it will work to balance things out.

Strength training will keep your metabolism at its peak. Most of us prefer cardio exercise over strength training, but lifting weights – your own or the ones you buy from the store or find at the gym – is absolutely key to losing weight and keeping it off. When we lose weight we don’t just lose body fat, we also lose precious muscle mass. This muscle mass is what keeps our metabolism revved up. Three to four strength training sessions a week with weights, tubes and medicine balls will help you maintain the muscle mass that you’re going to need to lose weight and keep it off.

HIIT training trumps steady state cardio. High intensity interval training isn’t just more fun and effective than steady state cardio, it burns more calories both while we’re engaged in the training and for up to 24 hours afterwards. Find a HIIT class at your local gym or do one in the comfort of your own home. HIIT training requires no equipment and there are some excellent workouts on YouTube that you can access for free. Below is a 20 minute HIIT workout from Pop Sugar that you can find on their YouTube Channel.

Protein helps retain muscle tissue. Eating a diet rich in lean protein will provide the fuel your muscles need to regenerate after both the strength training and HIIT workouts. Not having adequate amounts of protein can result in even greater muscle loss and a lower metabolic state.

Patience is a must-have. The best way to think about your diet is to reframe it so that you’re thinking about weight loss in terms of a lifelong health strategy not an unsustainable 12 week program. We already know that quick fix dieting programs are impossible to maintain so get a calendar and set a long-term goal. Journaling is a good way to hold yourself accountable to your program and writing down your successes and challenges will help you stay positive and persistent.

Bottom line is the more you shock your body by drastically reducing calories, the more it will fight you to maintain your body weight. A long term plan of eating nutrient-dense lower-calories whole foods, daily exercise that includes strength training, and a daily dose of patience and perseverance will give you the best results.