Friday, May 13, 2016

How much sleep do I need?

In the last few years, it has become evident that sleep deprivation has a negative impact on ability to lose weight. Although there is much left to learn about the mechanisms involved, it appears that at least 2 things happen to you when you do not get enough sleep:

1) Leptin levels drop. Leptin is a hormone that influences your metabolism. When leptin levels drop, you burn fewer calories.

2) Ghrelin levels increase. Ghrelin is a hormone that influences appetite. The higher the ghrelin, the more hungry you will be.

For obvious reasons, the combination of burning fewer calories and eating more because you are hungry makes it tough to lose weight.

Many studies over the last 10 years have shown a decreased metabolism and/or increased energy intake with sleep deprivation.

So, how much sleep do you need? Most studies show that 7 hours or more are what you are looking for. I have also found this to be true with my own clients.

Take a good look at your sleeping habits. Sleep deprivation can often be a little thought of, but very important component of your weight loss program.

Energy and macronutrient intake after gastric bypass surgery

The Study
Gastric bypass surgery is an effective strategy for weight loss in the severely obese when diet and exercise has not been effective. However, in most cases, 40-50% of lost weight is regained after several years and it is not clear why this is the case.

In this study, 16 women were followed for 3 years after bypass surgery. Total energy, lean body mass, and basal metabolic rate were measured at regular intervals during the follow-up. By the end of 12 months, the women had lost an average of 87 lbs.

At baseline, calorie consumption was 2,072 per day.

At 1 month post surgery, it dropped down to 681 calories.

At 12 months post surgery, it increased to 1240.

At 36 months, it increased to 1,448 calories.

As far as basal metabolic rate:

At baseline, it was 1.1 kcal/minute.

At 3 months it was .93 kcal/minute.

At 12 months it was .86 kcal/minute.

At 36 months is was .85 kcal/minute.

By the end of 1 month, 51.6% of weight lost was lean body mass. By the end of one year, 24.5% of weight lost was lean body mass. By the end of 36 months, 30% of weight lost was lean body mass. American Journal of Clinical Nutrition 2016; 103:18-24.

Take Home Message
This is a really important study, not just for those who have bypass surgery, but for everyone looking to keep lost weight off for good. Over the 3 years of this study, we saw a gradual increase in caloric consumption, a gradual decrease in basal metabolic rate, and a very significant loss in lean body mass.

Remember, lean body mass burns calories and is highly related to metabolism. You lose muscle, your metabolism drops and weight regain is far more likely. 

This study shows why a lot of people who get gastric bypass surgery regain their weight. They are the same reasons why the rest of us regain our weight; calories shoot back up and metabolism drops. 

The body may lower metabolism in response to weight loss. There is not much we can do about that. However, we can minimize loss of muscle mass by lifting weights consistently throughout the weight loss process and during weight maintenance. Keeping a close eye on caloric consumption is also essential to keeping the weight off.

This study would have been perfect if half the women were randomized to a weight lifting routine post surgery to compare basal metabolic rates and percent lean body mass lost.

Thursday, May 12, 2016

Probiotics and Weight Loss

The Study
Probiotics are live micro-organisms that have been shown to improve varying aspects of health when consumed in the proper quantities. It has been hypothesized that they increase rate of weight loss. In this randomized controlled trial, 89 overweight and obese women consumed a standard low fat yogurt, or a probiotic yogurt, for 12 weeks while following the same comprehensive weight loss program.

At the end of follow-up, women in both groups lost similar amounts of weight. However, the women consuming the probiotic yogurt had a 13.9 mg/dl drop in total cholesterol and a 13.5 mg/dl drop in LDL cholesterol when compared to the standard low fat yogurt group. They also had significant improvements in blood glucose and insulin levels. American Journal of Clinical Nutrition 2016; 103:323-29.

Take Home Message
This is a very nicely designed trial with a simple message. Probiotics can definitely improve certain health parameters but do not appear to increase the rate of weight loss. We are just beginning to learn about the health effects of the gut microbiota, but it appears to be an extremely important and complex element of good health. Unfortunately, it does not look like a quick fix for weight loss.


Feature Article: Do vegetarians live longer than meat eaters?

Vegetarians tend to avoid meat for one of 2 reasons, they think it is unhealthy to eat meat or they have an ethical issue with doing so. If they are motivated by ethical factors, that question is beyond the scope of this newsletter. If they are motivated by improved health, we can ask the question; Are vegetarians healthier than meat eaters? Do they live longer?

I recently came across a study that attempts to answer this question.

Mortality in vegetarians and comparable nonvegetarians in the United Kingdom. American Journal of Clinical Nutrition 2016;103:218-230.

This study was a pooled analysis of 2 prospective cohort studies in the UK that totaled 60,310 subjects: 

18,431 were regular meat eaters who ate meat 5 or more times per week.

13,039 were less frequent meat eaters.

8,516 were fish eaters who ate fish but not meat.

20,324 were vegetarians including 2,228 vegans who did not eat any animal foods.

Diet was assessed by means of a food frequency questionnaire. After over a million person years of follow-up time, there were 5,294 deaths before the age of 90. By the end of follow-up, there was no significant difference in total mortality among the 5 groups.

In other words, vegetarians and vegans did not live any longer than those that ate meat or fish.

I was not really surprised by the findings of this study. The idea that meat eaters are unhealthy while vegetarians are healthy is far too simplistic. There is a whole lot more to the story.

#1) Protein itself is not really the issue. It is what comes along with the protein package that will determine a food’s impact on health.

Healthy sources of protein will be low in saturated fat, unprocessed, low in sodium, and not red in color.

Examples of healthy protein sources would be lean meats like chicken and turkey, low fat dairy products, legumes, nuts, fish and seafood. You can see that some of these are animal sources and some are not.

Proteins you want to go a bit easier on include red meat, processed meats (like bacon, sausage, pepperoni, and hot dogs) and full fat dairy products like cheese. Again, some of these are animal sources and some are not.

2) When evaluating the health impact of a diet, you have to look at more than just the source of protein. For example, what is the quality of carbohydrate consumed? What type of fat is being consumed? If you are eating a ton of saturated fat, sugar and high glycemic load carbs, you are not going to be healthy no matter what protein sources you are focusing on.

For example a meat eater and a vegetarian can go out to a restaurant for lunch and order the following:

1) Meat eater: A garden salad with grilled chicken and olive oil and vinegar dressing, a glass of club soda with lime and a bowl of strawberries for dessert.

2) Vegetarian: Pasta Alfredo with two big pieces of bread, 2 sugary sodas and an ice cream sundae for desert.

Who did a better job, the vegetarian or the meat eater?

So, the take home messages from this study are the following:
1) Lean sources of animal protein like chicken, turkey, fish, and seafood are not bad for your health. There is no reason to avoid them.

2) The protein sources to strictly limit include processed meats like bacon, salami and hot dogs, red meat, dairy products like cheese, yogurt and milk that are full fat.

3) There are other important factors besides the source of protein in your diet that will impact your risk of chronic disease. Make sure you are paying good attention to your sources of fat and carbohydrate. Other important areas that need attention are your weight, exercise habits, sleep and stress levels.