It's that time of year again. It's the time of year where people say, "Screw it, I'll get back on the wagon after New Years!" This statement is followed by unfettered food consumption and little to no physical activity for 6 weeks followed by a crash diet and Tasmanian Devil levels of physical activity to work off what was put on over the holidays, not to mention the other 5 lbs you gained prior to the binge. What people fail to realize is that their failure was sealed long before they decided to throw caution to the wind and see how many holiday cookies they could eat without getting up on Thanksgiving day.
It's should come as no surprise to anyone that as we get older, our metabolism slows down. What may come as a surprise to most people, if not all, is that research shows that the crash diet you participated in last year probably jeopardized your chance at success this year. Hormones controlling everything from appetite to how much energy you burn take a hit from low calorie dieting, and the negative effect 10 weeks of low calorie dieting has on many of these hormones persists for a year or more(1).
This is one of the many reasons I tell people to stay away from anything like the Isagenix or Medifast programs, short-term results for long-term failure. If you are wondering how I jumped from a low calorie diet to either one of these programs, it's because the low calorie diet in the study above used essentially the same program, Optifast. They all follow the same template, consume 3-5 of our supplements per day, eat little to no food, and watch the fat melt away. What's even more disappointing is that these programs often tout that they are perfectly healthy since they provide 100% of the RDI(Reference daily intake) for micronutrients while also creating a caloric deficit. This may not be the case.
A small study looking at serum and intracellular micronutrient levels in obese people losing weight on the Optifast system paints a starkly different picture. The study followed obese people after following the Optifast 52 plan for 3 months and through 26 weeks of follow-up. It's not surprising that the diet of the participants before the study did not meet the RDI for several micronutrients and many were, therefore, found to have insufficient serum and intracellular levels of multiple micronutrients. What is surprising is that after 3 months of low calorie dieting with shakes that did meet or exceed the RDI of all essential micronutrients, more of the subjects experienced micronutrient deficiencies and some of the micronutrient deficiencies grew worse, particularly Vitamin C, selenium, iron, zinc, and lycopene(2). That doesn't seem very healthy to me.
Some of this can be explained by increased nutrient demand due to weight loss. However, if scientists are a little fuzzy on the micronutrient needs of people participating in a weight loss program, how well read up do you think the person who sold you this product is on the topic? Keep in mind Optifast is only administered by "qualified healthcare providers", which is basically code for someone with an MD who knows nothing about diet. Do you really think the guy at the gym who is schlepping this stuff to you based solely on his personal experience with it has any idea if it's healthy for you?
Interestingly, the participants in the second study who were able to maintain the
fat loss through follow up were able to improve these deficiencies as
they began eating real food. If they were able to maintain the
weight loss eating real food, why not just start there and not risk long
term hormonal dsyregulation due to the low calorie diet? The first
study we looked at showed this altered hormonal state lasts a year and,
unfortunately, follow up in this study only lasted 26 weeks. Who knows
if that weight loss was maintained or not? Maybe this holiday season would be better spent with sane levels of holiday food consumption and high levels of physical activity followed by a nutritious whole food diet at a slight caloric deficit and intelligently programmed exercise?