Tag Archive for: weight

Does a Little Extra Weight Keep You Alive?

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The Rotterdam Study was begun in 1991 to investigate the risk factors of cardiovascular, neurological, ophthalmological, and endocrine diseases in people 55 and older (1). The study is still ongoing, but periodically subsets of subjects are examined to find out which characteristics are associated with these diseases. In a study published in 2001, researchers reported on a group of subjects who were diagnosed with heart failure at the beginning of the study and followed for an average of six years—181 out of over 5,000 subjects. By the end of five years, 85 subjects had died. One of the observations that researchers noted was that a higher BMI was associated with reduced mortality; in plain terms, the heavier people were more likely to stay alive.

It didn’t stop there. In 2013, a study was published that directly examined the relationship between BMI and mortality (2). This meta-analysis included 97 studies and examined more than 2.88 million participants and more than 270,000 deaths. They reported that while grades 2 and 3 obesity (grade 2: BMI of 35-39.9; grade 3: BMI more than 40) were associated with increased mortality, grade 1 (BMI of 30-34.9) was not, and the overweight category (BMI of 25-29.9) actually showed a reduced risk of dying. (How do you rate? Check your BMI here.)

Is this true? Is body weight not associated with an increased risk of death? Have we been trying to lose weight for no reason? I’ll finish this on Saturday.

What are you prepared to do today?

Dr. Chet

 

References:
1. European Heart Journal (2001) 22, 1318–1327.
2. JAMA. 2013 January 2; 309(1): 71–82.

 

What Is the Obesity Paradox?

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Did you ever hear something that didn’t seem to make sense? That seemed to go against everything you thought to be true? One example of this is something called “The Obesity Paradox.” I’ve seen a few headlines this week that have talked about it, so it’s time to address it in the Memo.

One of the variables that we would think is related to the development of cardiovascular disease would be body weight. It seems logical: as weight increases, so does the strain on pumping the blood through the additional blood vessels required to feed the extra fat and muscle. People who are overweight may eat the wrong foods, consume too much food, and move too little.

But since the early 2000s, several studies have been published seeming to show that body weight wasn’t necessarily a risk factor for CVD or an early death. They showed that those who were overweight, a BMI between 25.0 and 29.9, had lower mortality rates than those who were normal weight. Some showed that stage-one obesity, a BMI between 30.0 and 34.9, was also not related to mortality. Thus the term “The Obesity Paradox” was coined. But is it true? We’ll take a look at the research the rest of the week.

What are you prepared to do today?

Dr. Chet

 

Sleep More and Quit Eating Sooner

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Sleep more, eat the same, and lose weight. Seriously? That’s what researchers are going to try to find out. At this point, there’s little question that for most people, lack of sleep messes with the circadian rhythms and negatively impacts glucose metabolism.

But a different research team is looking at another element: how long you eat every day can impact your ability to lose weight. Researchers have done a pilot study looking at eating intervals: the time you eat your first meal until you stop eating for the day. For people devoted to their evening snacks, it can be 16 to 18 hours per day.

In the pilot study, subjects restricted their eating to a period of 10 to 12 hours per day. Over 16 weeks, subjects lost an average of seven pounds. One more thing: they didn’t have to restrict their eating. They ate what they wanted, just in a shorter time interval every day.

This was a pilot study using an app that the researchers developed; they’re recruiting 10,000 subjects to see if the idea will work on a greater scale while collecting additional data. Such as what? Well, maybe you actually eat fewer calories when you eat in smaller time frame even if you eat the same foods. By the way, if you want to be a subject, check out www.mycircadianclock.org to see if you qualify.

Back to the sleep portion. The part that interests me the most is the messed up carbohydrate metabolism by eating when your clock says it’s time to sleep. Getting more sleep is not easy these days, but it just might be worth it.

We’ve all heard people say they cannot lose weight no matter what they do. Well, maybe getting a little more sleep and eating over fewer hours may help. Of course, if you’re a diabetic or hypoglycemic, talk with your doctor. But here’s something simple and cheap you could do: sleep more and eat the same over fewer hours. Will you lose weight? We don’t know, but it’s worth a try.

What are you prepared to do today?

Dr. Chet

 

Reference: doi:10.1001/jama.2017.0653

 

Can You Lose Weight by Sleeping More?

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That doesn’t seem to make any sense; you’re not going to be as active because you’re sleeping, so how can that help you lose weight? Well, if you’re sleeping you’re not eating, but there must be more to it than that. Let’s go back to the SCN, the pacemaker of rhythms.

Researchers have found that cortisol and melatonin aren’t the only hormones and organs tied to the light-dark cycles. Hundreds if not thousands of genes also respond to light-dark cycles. Glucose metabolism, the processing of sugars, is tied to these cycles; we seem to process sugars better during the light hours than at night. For some reason, eating carbohydrates in the dark hours results in slow processing of carbohydrates. Typically carbohydrate metabolism is a fairly high-energy process using 15 to 20% of the calories in digestion and absorption, but eating in the evening seems to decrease metabolism enough that it could theoretically result in gaining 12.5 pounds in a year.

Theory and life are two different things. Research on rodents shows that if researchers flip their cycle by feeding them in opposition to their rhythms—they’re day-sleepers, so they’re the opposite of us—they gain more weight when fed the same diet than mice fed during their normal cycle.

What about humans? Is there a solution? Skinny rats are fine, but what’s in it for us? We’ll wrap this up on Saturday.

What are you prepared to do today?

Dr. Chet

 

Reference: doi:10.1001/jama.2017.0653

 

Could Your Rhythms Be Keeping You Fat?

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You eat well and you exercise, but you still can’t lose any weight. What if the answer was in the natural rhythms of your body? I’m not talking about dance moves; I’m talking about circadian rhythms, the natural 24-hour cycles based on day and night. Since we can pretty much control the amount of light indoors 24-hours per day, our natural rhythms can be in disarray.

I’ve talked about the pacemaker of the heart several times over the years. It turns out that there’s an area in the brain called the superchiasmatic nucleus (SCN) that acts as the central pacemaker for circadian rhythms. It’s found in the hypothalamus and for a small group of cells, it seems to do a lot.

In the mornings in response to daylight, the SCN sends signals to raise body temperature and produce hormones such as cortisol. Time to get up! The SCN also responds to light by delaying the release of other hormones such as melatonin that help us sleep. When it gets dark the eyes signal the SCN that it’s night. Melatonin levels rise in the evening and stay elevated throughout the night, promoting sleep.

What does this have to do with being fat and not being able to lose weight? Now that we know how this pacemaker works, it turns out it could be an important factor. I’ll cover recent research the rest of the week.

What are you prepared to do today?

Dr. Chet

 

Reference: www.sleepfoundation.org.

 

Obesity: A Global Problem

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The overwhelming conclusion by the Global BMI Mortality Collaboration is that the rate of mortality linked with the degree of obesity follows the same pattern in the entire world with one exception: South Asia. If you look at the graphs of the mortality rate per BMI category, they’re virtually identical in North America, Europe, Australia, New Zealand, and East Asia. One of the reasons that South Asia might be different was that only three studies were included in the analysis.

We are not alone in our fight to lose weight and get healthier. Actually, that’s a completely different . . .

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Death by Obesity

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The Global BMI Mortality Collaboration examined the mortality of being overweight and obese in most parts of the world. They purposefully did not include people in the meta-analysis who had ever smoked or had a chronic disease when the study began; that makes sense because both can affect mortality within the five-year span they were examining. The range of the subjects was 20 to 89 years old and a BMI greater than 15.0.

They performed a hazard ratio analysis of the combined data, which examines the rate of an event (in this case death) within each weight . . .

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The World’s State of Obesity

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A week ago, I talked to a reader and visitor to my website who continues to check her BMI occasionally to see where she stands; she still hasn’t made it to the normal range but continues to try. I understand—I’m not there yet either. But there’s good reason to keep trying based on a recently published study.

The Global BMI Mortality Collaboration decided to examine the deaths from overweight and obesity in the entire world. Sometimes we think that the U.S. is the only overweight nation in the . . .

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Lessons from “The Biggest Loser”

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The recent study on weight gain by former participants in “The Biggest Loser” reality television show blamed decreases in resting metabolic rate (RMR): the decrease in RMR became worse over time and contributed to most of the participants regaining most of the weight. In other words, they ruined their resting metabolism.

No, they didn’t. In my opinion, there are errors in the measurements for RMR and total energy expenditure (TEE). The errors may be in the equipment, but more than likely, in the assumptions that were made in the calculations.

Here’s where I think researchers went wrong: there . . .

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Rate of Change

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I spent hours looking at the data in “The Biggest Loser” study. I did numerous calculations trying to figure out where the changes in caloric use occurred that could explain the dip in resting metabolic rate that made the headlines. There are several possible explanations.

Today I’ll give you the most probable reason: the subjects lost weight too fast. The average was 4.25 pounds per week and for some, it was double that. While that can win contests, it doesn’t allow the body to adjust to the tremendous changes that should be occurring.

Think about it. There . . .

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