Saturday, May 13, 2017

Visual cues and subsequent energy intake

The Study
Larger portion sizes have been shown to increase energy intake in the research literature. A recently published study attempts to explain why. Thirty-six children between the ages of 7 and 10 were shown a variety of pictures while undergoing a brain MRI scan. Some of the pictures were of large portion sizes, some were of small portion sizes. Some of the pictures where of high energy density junk foods (like chicken nuggets, French fries and cookies) and some were of low energy density healthy foods (like grilled chicken, green beans and blueberries).

The results were fascinating. When the children were shown pictures of foods with large portion sizes, there was a decrease in activity in the region of the brain called the inferior frontal gyrus. This region is important for inhibition. When the children were shown pictures of the high energy density junk food, there was an increased activation in the insula, caudate and cingulate. These parts of the brain deal with reward and taste processing. American Journal of Clinical Nutrition 2017; 105:295-305.

Take Home Message
This is a really interesting study. Just seeing pictures of foods that were large in portions or energy dense changed the brain in a way that increased the desire to overeat. When I first started studying nutrition and weight loss in the early 2000’s, the prevailing wisdom was that losing weight was simply about eating less and exercising more. 

It is now clear that there is a lot more going on. There are a multitude of factors that impact our food choices and cravings. The results of this study add simple visual cues to the growing and complex list of body systems that impact what we eat and how much we eat. We are learning a lot but still have a ways to go. If you find yourself in the presence of tempting foods that you do not want to eat, look away! J

Changes in skeletal muscle and organ size after weight loss

The Study
Most people who lose weight have a really hard time keeping it off. This is largely due to a drop in resting energy expenditure after weight loss. The goal of this study was to learn more about the root cause of the metabolic decrease that accompanies weight loss. For this investigation, 53 men and 39 women with type 2 diabetes were randomly assigned to one of two groups. The first group had an intensive diet and exercise intervention to help them lose weight. The second group had diabetes support and education, but did not lose weight. MRI scans were performed on all subjects at the end of one year and then again at the end of the second year.

The results were very interesting. By the end of 1 year, only the diet and exercise group lost weight (14.5 pounds on average). The diet and exercise group lost a bit more muscle during the first year (about ½ a pound), but also had significant reductions in the size of their spleen and liver when compared to the control group. American Journal of Clinical Nutrition 2017; 105:78-84.

Take Home Message
This is a pretty cool study. The intervention that helped these subjects lose weight was really heavy on exercise, which is why they maintained a lot of their muscle. The fact that their organs decreased in size is fascinating. Organs like the liver, spleen, heart, and kidneys burn a lot of calories. The fact that they may get smaller after weight loss may explain a lot of the decrease in metabolic rate seen after weight loss. 

The take home message is the following: lift weights at least twice per week when trying to lose weight. This will minimize the loss of lean muscle tissue and make it much easier to keep the weight you lose off permanently. We need to learn more about the decrease in organ size and how this may impact our ability to keep weight off. Stay tuned.

Product Review: Bodylastics Resistance Bands

When I was in college and even grad school, there always seemed to be plenty of time to get to the gym and enjoy a leisurely workout. Now that I’m older, time is definitely more limited. I’ve noticed the same thing with the majority of my clients over the years. At the end of the day, it is just not realistic for most people to get the gym on a daily basis. It is for this reason that I am a huge proponent of working out at home.

You do not need a lot of space or equipment to successfully exercise at home. An inexpensive piece of cardio equipment (such as the Gazelle Edge), a flat bench and some dumbbells will get the job done quite well for most people. However, working out your back can be a bit more challenging in the home environment. There are a few dumbbell exercises that focus on the back, but to really get the variety you want, you’ll need to bring in some other equipment. I figured I’d use this post to introduce one such piece of equipment: Bodylastics Resistance Bands.  

Bodylastics Resistance Bands are a stackable and adjustable resistance system. The version that I purchased has 96 pounds of resistance, but they also sell versions with more or less resistance. The system comes with 4 different colored bands of varying thickness that you can combine to produce the exact resistance you need for any exercise.

In addition to the stackable resistance bands, the system comes with hand and ankle handles, as well as a door anchor. The door anchor is the absolute key. It allows you to attach the system to any door that closes in your home. If you put it up high, you can simulate high pulley exercises, like lat pull downs. If you keep the anchor a bit lower, you can simulate low pulley exercises, like seated rows. This adds a completely new element to how you can work your back at home. Let’s take a quick look at the pros and cons of the Bodylastics system.

1) Extremely Well Made And Durable: I’ve had my bands for 6 years and they are showing no signs of wear and tear.

2) Serious Resistance: I’ve historically been a bit down on resistance bands in general. I never felt like I was getting the type of resistance that I needed. Not so with the Bodylastics system. These feel a lot tighter than other bands I’ve used. I get a great workout with these.

3) Comes With A Door Anchor: Great for working the back with simulated high and low pulley exercises.

4) Very Portable: The system comes with a carrying case that can easily fit in your luggage for when you need to bring your workout on the road.

5) Very Secure Door Anchor: Door anchors tend to make me nervous. Not this one. It is solid and it’s going no where, so feel free to workout with confidence.

1) The only con that I can come up with is the price. They are a bit more expensive than other resistance bands. They retail for $54.95, but as of this writing, has them on sale for $29.95, which is a great price while it lasts.

Do I Recommend Bodylastics Resistance Bands?
Absolutely. These are a great addition to any home gym and will allow you to be much more creative with your workouts. While they cost a bit more than other bands on the market, the quality of this product easily makes it worth the extra investment. To learn more about these bands or to pick them up, check out their amazon page (here).

Disclosure: I am not affiliated with the company that makes these bands and make no money if you buy them.  I just think they are great and want to let you know.