Does Genetics Determine Weight?

Written by Dr. Steve Chaney on . Posted in Health Current Events, Healthy Lifestyle, Obesity

Does Genetics Cause Obesity?

Author: Dr. Stephen Chaney

Overweight & Skinny WomenIt’s frustrating. Try as hard as you might, you just can’t seem to lose weight. Even worse you suspect that your friends – and maybe your doctor – assume that you are cheating on your diet. It just doesn’t seem fair.

Perhaps there is a simple explanation. Maybe your genes are keeping you from losing weight. Does genetics determine weight?  It has been hypothesized that some of us have a “thrifty” phenotype when it comes to weight loss while others are “spendthrifts”. The theory is that people with a “thrifty” phenotype hold on to weight more tightly when they are “fasting” (i.e. trying to lose weight) and gain weight more readily when they are “feasting” (i.e. eating excess calories).

The metabolism of the “spendthrifts” is exactly the opposite. They lose weight rapidly when fasting and gain weight slowly when feasting. Those would be all of your skinny friends who just can’t seem to understand why you have such difficulty losing weight.

Those experts who favor the “thrifty” phenotype hypothesis point out that it would have provided a tremendous survival advantage in prehistoric times when food was scarce. That’s why some of those same experts think that up to 80% of the population has the “thrifty” phenotype. When you couple the thrifty phenotype with the typical American diet and lifestyle it becomes easy to understand why we have an obesity epidemic in this country.

Is the “thrifty” phenotype hypothesis true? Could it explain why you have such difficulty losing weight? A recent study suggests the answer to those two questions may be yes. I will outline the evidence below.

Then I will address what are probably the two most important questions for you: “If the thrifty phenotype hypothesis is true and you have the thrifty phenotype, are you destined to be overweight? Is there anything you can do about it?

How The Study Was Designed

medical studyThis study (Reinhardt et al, Diabetes, 64: 2859-2867, 2015) was truly a remarkable study. 15 healthy, but obese volunteers were put in a metabolic ward for a total of 11 weeks. In the metabolic ward every aspect of their metabolism was closely controlled and measured.

  • They were given diets that were precisely calibrated to provide a predetermined caloric (energy) input.
  • Urine and feces were collected and analyzed in an instrument called a bomb calorimeter to determine calorie (energy) output.
  • They were limited to primarily sedentary activity for the duration of the experiments, and the temperature of the metabolic ward was maintained constant. This eliminated variation in energy expenditures due to activity and temperature.
  • Metabolic energy expenditure was calculated by placing them in a special room designed to precisely measure oxygen consumption and CO2 production by the subjects over a 24 hour period. Don’t worry about the details. Just know that this is the gold standard for measuring energy expenditure.

Here is what the subject’s 11 weeks in the metabolic ward looked like:

  • During the first 3 weeks the subjects were provided with a diet designed with just enough calories to maintain their weight based on their weight and sex. If weight gain or loss was observed the calories were adjusted accordingly.
  • During one 24 hour period in week 3 the subjects were place on a diet that decreased their calories by 50%, (defined as “fasting” in this study) and the resulting decrease in metabolic energy expenditure was measured as described above.
  • During another 24 hour period in week 3 the subjects were place on a diet that increased their calories by 200% (defined as “overfeeding” in this study), and the resulting increase in metabolic energy expenditure was measured.
  • During the next 6 weeks the subjects were placed on calorie restricted diet that only provided 50% of the calories they needed to lose weight.
  • During the final 2 weeks the subjects were placed on a diet designed to provide the calories needed to maintain their new weight, whatever it was.

How Does Genetics Determine Weight?

do genetics cause obesityThe results of the study were quite interesting:

  • All of the subjects lost weight, but the amount of weight loss ranged from 5% to 12% of the original body weight.
  • Their starting weight did not influence their rate of weight loss during calorie restriction, but their metabolic response to fasting and overfeeding significantly affected their rate of weight loss. Specifically:
  • The subjects with the smallest decrease in energy expenditure during fasting and the largest increase in energy expenditure during overfeeding (the spendthrifts) lost significantly more weight during the 6 week caloric restriction period (what most of us call a diet).
  • The subjects with the largest decrease in energy expenditure during fasting and the smallest increase in energy expenditure during overfeeding (the thrifty) lost significantly less weight during the 6 week caloric restriction period.
  • The amount of caloric restriction needed to lose one pound of weight ranged from 1,558-2,993 depending on whether the subjects displayed the spendthrift or thrifty phenotype. That’s almost a 2-fold difference.

What Does This Study Mean For You?

life-is-sometimes-unfairLife isn’t fair. You probably already suspected that. Your skinny friends actually do have a much easier time losing weight than you do. In fact, they may be able to lose up to twice the amount of weight with exactly the same amount of caloric restriction.

However, the good news is that weight loss is possible – even for you. Everyone in the study lost weight – even those subjects with the thriftiest phenotype. So the question becomes what can you do to lose weight successfully? Here are 5 simple tips.

#1: Don’t give up. Stick with it. Pounds may come off slowly for you, but this study shows they will come off. You just have to keep the faith and be consistent.

#2: Watch what you eat very carefully. The researchers in this study controlled every morsel of food the subjects ate. People always lose weight more rapidly when they are in a metabolic ward. My recommendation is to track what you eat daily using one of the many available tracking apps.

#3: Be consistent with your exercise. The subjects in this study were not allowed to exercise, but that is one of the best ways to increase energy expenditure. Aerobic exercise gives you a small increase in energy expenditure during and immediately following the exercise. Weight bearing exercise gives a long term increase in energy expenditure because it increases muscle mass, and muscle burns calories faster than any other tissue.

#4: Choose a diet that preserves muscle mass (High Protein Diets and Weight Loss ) while you are losing weight.

#5: Avoid all those diets with herbal and pharmaceutical stimulants. They are dangerous and they may just kill you.  Check out  Are Dietary Supplements Safe.

 

The Bottom Line

A recent study (Reinhardt et al, Diabetes, 64: 2859-2867, 2015) did a very careful metabolic analysis and divided subjects into what they characterized as either a “thrifty” or “spendthrift” phenotype based on their changes in metabolic energy expenditure in response to fasting and overfeeding. They then looked at how those phenotypes affected weight loss during a 6 week period of caloric restriction. Does genetics cause obesity or help determine weight?  Here’s what they found:

  • All of the subjects lost weight, but the amount of weight loss ranged from 5% to 12% of the original body weight.
  • Their starting weight did not influence their rate of weight loss during caloric restriction, but their metabolic response to fasting and overfeeding significantly affected their rate of weight loss. Specifically:
  • The subjects with the smallest decrease in energy expenditure during fasting and the largest increase in energy expenditure during overfeeding (the spendthrifts) lost significantly more weight during the 6 week caloric restriction period (what most of us call a diet).
  • The subjects with the largest decrease in energy expenditure during fasting and the smallest increase in energy expenditure during overfeeding (the thrifty) lost significantly less weight during the 6 week caloric restriction period.
  • If you struggle to lose weight, this is a good news – bad news study.
  • The bad news is that life isn’t fair. You probably already suspected that. Your skinny friends actually do have a much easier time losing weight than you do.
  • The good news is that weight loss is possible – even for you. Everyone in the study lost weight – even those subjects with the thriftiest phenotype. So the question becomes what can you do to lose weight successfully? I’ve given you 5 simple tips in the article above.

 

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure or prevent any disease.

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Latest Article

Omega-3 Benefits: Lower High Blood Pressure

Posted July 16, 2019 by Dr. Steve Chaney

What Does the FDA Say About Omega-3 Benefit Claims?

Author: Dr. Stephen Chaney

 

 

Among omega-3 benefits is lower high blood pressure.  That claim can be made according to the FDA. 

lower high blood pressureHeart Disease is still the number 1 cause of death in this country. And, while deaths from heart disease have been declining in recent years, deaths due to high blood pressure have been increasing.  That is concerning because:

High blood pressure is a killer! It can kill you by causing heart attacks, strokes, congestive heart failure, kidney failure and much more.

High blood pressure is a serial killer. It doesn’t just kill a few people. It kills lots of people. The American Heart Association estimates that high blood pressure directly or indirectly caused 410,000 deaths in 2014. That is almost 1 person every second and represents a 41% increase from 2000. It’s because high blood pressure is not a rare disease.

  • 32% of Americans have high blood pressure, also called hypertension, (defined as a systolic blood pressure of 140 mm Hg or more or a diastolic blood pressure of 90 mm Hg or more).
  • Another 33% of Americans have prehypertension (systolic blood pressure of 120-139 mm Hg or diastolic blood pressure of 80-89 mm Hg).

That’s over 65% of Americans with abnormal blood pressure!

High blood pressure is a silent killer. That’s because it is a very insidious disease that sneaks up on you when you least expect it. Systolic blood pressure increases 0.6 mm Hg/year for most adults over 50. By age 75 or above 76-80% of American adults will have high blood pressure.  Even worse, many people with high blood pressure have no symptoms, so they don’t even know that their blood pressure is elevated. For them the first symptom of high blood pressure is often sudden death.

Blood pressure medications can harm your quality of life. Blood pressure medications save lives. However, like most drugs, blood pressure medications have a plethora of side effects – including weakness, dizziness, fainting, shortness of breath, chest pain, nausea, diarrhea or constipation, heartburn, depression, heart palpitations, and even memory loss. The many side effects associated with blood pressure medications lead to poor compliance, which is probably why only 46% of patients with high blood pressure are adequately controlled.

You do have natural options. By now you are probably wondering whether there are natural approaches for controlling your blood pressure that are both effective and lack side effects. The answer is a resounding YES! I’ll outline a holistic natural approach for keeping your blood pressure under control in a minute but let me start with the FDAs recent approval of what they call “qualified claims” that omega-3s lower blood pressure.

 

What Does the FDA Say About Omega-3 Benefits?

omega-3 benefitsIn my book “Slaying The Supplement Myths” I talk about the “dark side” of the supplement industry. There are far too many companies who try to dupe the public by making outrageous and unsubstantiated claims about their products.

Only the FDA stands between us and those unscrupulous companies, and they take their role very seriously. That is why it is big news whenever the FDA allows companies to make health claims about their products.

Even then, the FDA is very cautious. They allow what they call “qualified” health claims. Basically, that means they are saying there is enough evidence that the health claim is probably true, but not enough evidence to say it is proven.

Of course, if you understand the scientific method, you realize there will always be some studies on both sides of every issue. That is why the only health claims the FDA allows are qualified health claims.

With that background in mind, let’s look at the qualified health claims the FDA allows for omega-3 benefits.

  • Since 2004 the FDA has allowed the qualified claim “Supportive but not conclusive research shows that consumption of EPA and DHA omega-3 fatty acids may reduce the risk of coronary heart disease.”
  • A few weeks ago, they added five qualified health claims about omega-3s and blood pressure. The 5 claims are very similar, so I will only list two below for the sake of brevity.
  • “Consuming EPA and DHA combined may reduce blood pressure and reduce the risk of hypertension, a risk factor for CHD (coronary heart disease).”
  • Consuming EPA and DHA combined may reduce the risk of CHD (coronary heart disease) by lowering blood pressure.
  • Of course, they add the usual wording about the evidence being inconsistent and inconclusive.

 

Omega-3 Benefits?

measure omega-3 benefits levelWe’ve known for some time that omega-3 fatty acids help lower blood pressure, but two recent studies were instrumental in convincing the FDA to allow these qualified health claims. These studies have highlighted just how strong the effect of omega-3s on lowering blood pressure is.

The first study was a meta-analysis of 70 randomized, placebo-controlled clinical trials of long chain omega-3 (EPA + DHA) supplementation and blood pressure (Miller et al, American Journal of Hypertension, 27: 885-896, 2014 ).

This study showed:

  • In the group with normal blood pressure at the beginning of the study EPA + DHA supplementation decreased systolic blood pressure by 1.25 mm Hg.
  • Given that systolic blood pressure rises an average of 0.6 mm Hg/year in adults over 50, the authors estimated that omega-3 supplementation alone would delay the onset of age-related high blood pressure by 2 years.
  • In the group with elevated blood pressure not taking medication at the beginning of the study, EPA + DHA supplementation decreased systolic blood pressure by an impressive 4.51 mm Hg and diastolic blood pressure by 3.05 mm Hg.
  • The authors noted that this decrease in systolic blood pressure could “prevent an individual from requiring medication [with all its side effects] to control their hypertension” or decrease the amount of medication required.

However, the doses of omega-3s used in these studies ranged from 1 to over 4 grams/day (mean dose = 3.8 grams/day). That sparked a second study (Minihane et al, Journal of Nutrition, 146: 516-523, 2016) to see whether lower levels of omega-3s might be equally effective. This study was an 8-week double-blind, placebo-controlled study comparing the effects of 0.7 or 1.8 grams of EPA + DHA per day (versus an 8:2 ratio of palm and soybean oil as a placebo) on blood pressure.

This study showed:

  • In the group with normal blood pressure at the beginning of the study, EPA + DHA supplementation caused no significant decrease in blood pressure. This could be due to the smaller number of subjects or the lower doses of EPA + DHA used in this study.
  • In the group with elevated blood pressure not taking medication at the beginning of the study, EPA + DHA supplementation decreased systolic blood pressure by 5 mm Hg and, the effect was essentially identical at 0.7 grams/day and 1.8 grams/day.
  • The authors concluded “Our data suggest that increased EPA + DHA intakes of only 0.7 grams/day may be an effective strategy for blood pressure control.”

 

A Holistic Approach to Lower High Blood Pressure

holistic approach to lower high blood pressureThe FDA’s allowed claims about omega-3s are good news indeed, but that’s not the only natural approach that lowers blood pressure. You have lots of other arrows in your quiver. For example:

  • The DASH diet (A diet that has lots of fresh fruits and vegetables; includes whole grains, low fat dairy, poultry, fish, beans, nuts and oils; and is low in sugar and red meats) reduces systolic blood pressure by 5-6 mm Hg. [Low fat, low carb and Mediterranean diets also lower blood pressure, but not by as much as the DASH diet].
  • Reducing sodium by about 1,150 mg/day reduces systolic blood pressure by 3-4 mm Hg.
  • Reducing excess weight by 5% reduces systolic blood pressure by 3 points.
  • Doing at least 40 minutes of aerobic exercise 3-4 times/week reduces systolic blood pressure by 2-5 mm Hg.
  • Nitrates, whether derived from fresh fruits and vegetables or from supplements probably also reduce blood pressure, but we don’t yet know by how much.

If you’ve been keeping track, you’ve probably figured out that a holistic lifestyle that included at least 0.7 grams/day of long chain omega-3s (EPA + DHA) plus the other omega-3 benefits in the list above could reduce your systolic blood pressure by a whopping 18-22 mm Hg.  What

That’s significant because, the CDC estimates that reducing high systolic blood pressure by only 12-13 mm Hg could reduce your risk of:

  • Stroke by 37%.
  • Coronary heart disease by 21%.
  • Death from cardiovascular disease by 25%.
  • Death from all causes by 13%.

 

A Word of Caution

While holistic approaches have the potential to keep your blood pressure under control without the side effects of medications, it is important not to blindly rely on holistic approaches alone. There are also genetic and environmental risk factors involved in determining blood pressure. You could be doing everything right and still have high blood pressure. Plus, you need to remember that high blood pressure is a silent killer that often doesn’t have any detectable symptoms prior to that first heart attack or stroke.

My recommendations are:

  • Monitor your blood pressure on a regular basis.
  • If your blood pressure starts to become elevated, consult with your doctor about starting with natural approaches to bring your blood pressure back under control. Doctors are fully aware of the side effects of blood pressure medications, and most doctors are happy to encourage you to try natural approaches first.
  • Continue to monitor blood pressure as directed by your doctor. If natural approaches are insufficient to bring your blood pressure under control, they will prescribe the lowest dose of blood pressure medication possible to get your blood pressure where it needs to be.
  • Don’t stop making holistic lifestyle choices to reduce blood pressure just because you are on medication. The more you do to keep your blood pressure under control with a healthy diet and lifestyle, the less medication your doctor will need to use (That means fewer side effects).

 

The Bottom Line

Heart Disease is still the number 1 cause of death in this country. And, while deaths from heart disease have been declining in recent years, deaths due to high blood pressure have been increasing. That is why anything we can do lower blood pressure naturally is important. What does the FDA say about omega-3s and blood pressure?

  • Since 2004 the FDA has allowed the qualified claim “Supportive but not conclusive research shows that consumption of EPA and DHA omega-3 fatty acids may reduce the risk of coronary heart disease.”
  • A few weeks ago, they added qualified health claims about omega-3s and blood pressure. For example, they now allow the following claims.
  • “Consuming EPA and DHA combined may reduce blood pressure and reduce the risk of hypertension, a risk factor for CHD (coronary heart disease).”
  • Consuming EPA and DHA combined may reduce the risk of CHD (coronary heart disease) by lowering blood pressure.

For more information on the studies that convinced the FDA to allow claims about omega-3s and blood pressure and for a discussion of holistic natural approaches for lowering blood pressure, read the article above.

 

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure or prevent any disease.

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