Navigating Diet Induced Metabolic Decline

Losing weight can be a difficult endeavor, but nowhere near as difficult as keeping the weight off. Once we begin to eat what we consider to be a normal amount the weight just seems to go back on. If you have experienced this for yourself you would be correct and also not at fault. You see our bodies survival programing takes over and it takes diligent effort to overcome.

When we begin a caloric restriction diet our bodies take notice of the deceased energy intake. If the restriction is small it won’t fight you much at all, but over time or if the restriction is significant then various autonomic systems begin to counter the decreased energy consumption. Once our body gets used to carrying a certain amount of body fat anything less becomes a cause for concern. It responds by slowing metabolism, decreasing leptin (decreases appetite) and instead increasing ghrelin which increases hunger. The body will also begin to catabolize muscle to use as fuel as well as to slow metabolism further. This slows your weight loss while sparing some fat. If you happen to reach your weight loss goal once you begin to consume what would normally be maintenance calories you will notice gradual weight gain partly because of reduced metabolism.

To understand how much metabolism is affected by diet let’s look at a few studies. In a study by the American Diet Association test subjects were placed on a very low calorie diet for 12 weeks. Weight loss was significant, but so too was a 23.8% drop in resting metabolic rate. In another published article some subjects were placed on an 890 calorie per day diet until a 15% percent reduction in weight, followed by a maintenance period. At month 3 the subjects exhibited a 633 cal/day reduction in metabolism. Even after maintenance diet and accounting for their smaller size at 6 months their metabolism was still down 240cal/day. Finally in a short term effect study subjects placed on 1114 calories per day experienced a 13% drop in 4 days and those  at 1462 calories saw a 6% drop. These are significant numbers.

Now armed with this information what can we do about it? Is there a way to reset metabolism to our higher levels or does it stay decreased?  Let’s look at a few popular practices people use.

Cheat Meal

A cheat meal also sometimes called a free meal or treat meal is a refeeding that allows an increase in calories and likely some normally avoided foods; think pizza. The rational as to how this works is that the increased caloric intake increases the slowing metabolism while also satisfying cravings. Does this work…maybe? Research shows the metabolism can increase 15 – 30% after such a meal, however, only for at best 24 hours. The amount of increased metabolism wouldn’t actually even burn the additional calories consumed before slowing again. The real benefit seems to be in helping dieters stay on course and not feel deprived.

The MATADOR

The MATADOR or on again, off again diet consists of following a caloric restriction diet for 2 weeks followed by 2 weeks of maintenance calories and repeating the cycle. A study in the International Journal of obesity found that the subjects who followed this pattern lost more weight than their counterparts who followed a traditional course.  They also had an easier time following the diet. One caveat was it took twice as long to complete the weight loss course.  On your maintenance weeks you cannot deviate or exceed maintenance level calories.

10% Solution

This diet relies on the idea of Set Points, meaning your body fights to maintain a particular weight based partially on hereditary and environmental factors. Studies suggest your body will allow a 10% weight loss before fighting back. In this diet once you lose weight 10% of your weight you switch to a maintenance plan for 6 months before going for the next 10%. This in theory allows your Set Point to recalibrate to your new lower weight without sacrificing metabolism. This diet would take a significant amount of time depending on how much weight you need to lose, but because of the length of time involved you would also retrain your lifestyle choices.

How to make these diets work for you

Cheat meal - I personally like and use the cheat meal concept. It allows me to not feel confined or restricted. I generally save my cheat meal for the weekend when I am more likely to be social. To make this plan work remember it’s a cheat meal not a cheat day. Basically you have around 3 hours to enjoy your cravings. A cheat day would likely result in too many calories being consumed and therefor jeopardizing your weight loss results. For best results factor out what your daily maintenance or weight loss calories should be then multiply by 7. This should give you a total weekly caloric count. Divide this up including your cheat meal. So, for instance, let’s say your weight loss goal calories are 2000/day. Multiply this by 7and you get 14,000 calories. If your cheat meal is 1500 calories subtract this amount and you would have 12,500 calories left. Now divide this amount by 7…the answer is 1786. This is your daily amount allowed. On your cheat meal day you could have a whopping 3286 calories and still hit your weekly total.

MATADOR and 10% solution- These diets are marathons not sprints and if you can hang with these you should have lasting results mainly because you would have developed a new healthier lifestyle. As far as Set Points go, the theory is still being debated. It’s also likely that 3 months may be enough time to allow the body to adjust rather than waiting for 6. Lifestyle diets are a good option. Imagine if you just cut 250 calories a day from your diet in a year you would have lost 26 pounds.

Regardless of the plan here are a few helpful tips. Studies have shown that exercise can significantly lessen metabolism decline while dieting making it easier to maintain the weight loss, so increase your activity for best results. Different foods have different thermic effects on the body. Carbohydrates have a very low thermic effect (energy converted to heat) while protein has a high TE. Therefore eating less carbs and more protein would mean a higher metabolism. A study conducted at Framingham State University found that subjects who ate 60% of their calories from fat had on average 250 calories a day more metabolism compared to those who ate 60% of calories from carbohydrates.

Finally, consider over restricting calories will not only make you miserable, but also likely wreck your metabolism and long term results.

References:

Healthline.com – 6 mistakes that slow down your metabolism

Pubmed.ncbi.nim.nih.gov – metabolic and behavioral compensations in response to caloric restriction

Ncbi.nim.nih.gov/pmc/articles Metabolic response to short term 4 day energy restriction

Nm.org/healthbeat – the skinny on cheat days

Bidmc.org – Week one the science of set points

Pubmed.ncbi.nim.nih.gov  Effect of vert low calorie diet on body composition and resting metabolic rate

Medicinenet.com – The on again, off again weight loss diet

Pubmed.ncbi.nim.nih.gov – Impact of energy intake and exercise on resting metabolic rate