Can we lose weight by getting morning sunlight?
Well, the jury is still out on this one, but a new study suggests that there may be a connection between bright morning light and lower weight. Here is the latest research:
"Timing and Intensity of Light Correlate With Body Weight In Adults" http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0092251
And here is a good article with an interview with the lead researcher: http://healthyliving.msn.com/health-wellness/the-morning-light-may-help-you-stay-slim-1
"We were very interested in looking at the relationship between lighting and how that may be affecting your weight," explained study senior author Dr. Phyllis Zee, director of the sleep disorders center at Northwestern University Feinberg School of Medicine inChicago….Zee said the strongest association was seen in people exposed to light that was at least 500 lux, which is the equivalent of a well-lit indoor room. Outside on a sunny day provides 1,000 lux or higher, while most indoor rooms are about 200 to 250 lux, according to Zee...But, the timing of the light also mattered. Those who were exposed to brighter light earlier in the day were the slimmest."
Previous studies have also shown a connection between light, appetite, metabolism, and weight. From the PLOS ONE research article: "Several studies now indicate that morning light exposure influences body fat ,  as well as the level of appetite regulating hormones... leptin and ghrelin ...The results of this study demonstrate that the timing of even moderate intensity light exposure is independently associated with BMI….Our findings, similar to those from two different animal models ,  found that changes in the timing of light exposure were associated with body weight independent of caloric intake. One possible mechanism linking light directly to BMI, rather than caloric intake may be the influence of light on the expression and secretion of hormones, such as melatonin."
So, the research is still in early stages, we are not quite sure which hormones are being affected, and how the light might lead to lower weight. From a practical standpoint, should we do anything?
Well, it can't hurt to get out and get a morning walk in the sunlight. Heck, it might even help!
Tuesday, June 3, 2014
"Doc, will I lose more weight if I cut out diet soda?" I've heard this question many times, and this topic has been ALL over the internet since last week, when a new study came out about diet soda and weight loss. I realized it's time for me to blog about the Great Diet Soda Debate.
Diet soda (and artificial sweeteners) have become an emotional topic for some, and everyone needs to calm down, take a deep breath, look at what the study actually said, and then decide for themselves what they would like to do!
So, first of all, here are links to two good articles about the study: http://www.wmur.com/health/diet-soda-sometimes-help-with-weight-loss-study-finds/26180506#!T1Hzd
The new research was published May 27 in Obesity, the journal of The Obesity Society, and was co-authored by James O. Hill, who is well-known for his work with the National Weight Control Registry. http://www.nwcr.ws/people/Hill.htm To briefly summarize, researchers took a group of 303 people who were ALREADY DRINKING DIET SODA on a regular basis, and then told half the group they could continue diet soda, and instructed the other half to switch to water. They then followed them for 12 weeks, treating them with an 'aggressive' behavioral weight loss program, with intense counseling and guidance on nutrition, journaling, exercise, and behavioral strategies.
At the end of 12 weeks, they compared the amount of weight lost in each group - Group A who continued to drink their favorite diet soda, and Group B who quit diet soda, and switched to water. The results were surprising, to say the least. Lo and behold , Group A - those who continued to drink diet soda - actually LOST MORE WEIGHT than Group B - those who had stopped the diet soda and switched to water! Group A lost an average of 13 pounds, while Group B lost only 9 pounds. Group A - the diet soda drinkers - lost 44 % more weight!
How could this be? And why? Well, first of all, NO ONE thinks that diet soda is a magic weight loss trick. And second of all, it's important to remember that Group A, the 'bigger losers' did not ADD diet soda to their diets, they were already drinking it in the first place - they were just allowed to continue it. So, the suspicion is that Group A performed better, and lost more weight, because they were feeling content, satisfied that they could continue a favorite treat, so they AVOIDED A SENSE OF DEPRIVATION. Group B likely felt deprived of their favorite treat, and research shows that if people feel deprived, they are less likely to adhere to a healthy overall plan.
Dr. Hill noted, according the article on WMUR, "in his clinical experience, many people who have successfully lost significant weight "are heavy users of noncaloric sweeteners."...Cutting calories and boosting exercise takes a lot of willpower. Trying to simultaneously give up something else you regularly enjoy -- such as diet soda -- taxes your ability to stay the course. Most psychologists agree that our willpower is a limited resource…
"The most likely explanation was that having access to drinks with sweet taste helps the (artificially-sweetened beverage) group to adhere better to the behavioral change program."
Just how well did the group do who continued diet soda? According to the Science Daily article:
"In addition to losing 44 percent more weight than the control group, the diet beverage group also:
- Reported feeling significantly less hungry;
- Showed significantly greater improvements in serum levels of total cholesterol and low-density lipoprotein (LDL) -- the so-called "bad" cholesterol; and
- Saw a significant reduction in serum triglycerides."
And "Additional research published in 2009 on weight loss maintenance, drawn from the National Weight Control Registry, found that successful weight loss maintainers drank three times more diet beverages than those who had never lost weight."
On the other hand, some research has shown a correlation - not causation, but 'association' - between the long term use of diet (and regular) sodas with kidney disease, heart disease, and metabolic syndrome, among other possible problems. And some experts have speculated that drinking sweet tasting things might increase the desire/cravings for sweets (although this hasn't been proven for certain.)
So, what to do? It appears that if you are ALREADY using diet soda, and this is an important 'treat' for you, then it's probably not the best idea to try to cut this treat out while you are just starting a new healthy diet/exercise/behavioral weight control program. The sense of deprivation may weaken your willpower, and you might find it harder to stay on track with the rest of your healthy choices. Later, once you're "on a healthy roll" with your program, you may want to cut out diet soda to gain additional possible health benefits (such as a possible lower risk of kidney disease).
But if you find that cutting out your diet soda leaves you feeling deprived, and then you go off the rest of your healthy routine, you might want to add back in the occasional diet soda treat, if it's important to you! I just had a patient come in with this very problem. She had been doing REALLY well with healthy diet, exercise, and weight loss, but derailed herself when she stopped diet soda and ended up feeling deprived. She hadn't even heard about the recent study, but was feeling frustrated and angry at herself, and wanted to know what to do. We talked it through, and she is going to re-add the occasional diet soda - the 'risk' is certainly outweighed by the 'benefit' in her case!
Remember, the goal is PROGRESS NOT PERFECTION when it comes to healthy lifestyle. The goal is to be GOOD ENOUGH to get the health benefits we seek - NOT perfect. If you try too hard to be perfect, and you fall short, you might end up giving up ALL the healthy changes you've already made - and that would be a disaster! NO ONE is perfect (no one I've met anyway) and we have to pick and choose key healthy changes, and focus on those which are going to give us the 'biggest bang for the buck' in terms of health benefit. Remember - "don't let perfection become the enemy of the good" - to misquote Voltaire.
And don't let a SENSE OF DEPRIVATION DERAIL YOU!