Tag Archives: obesity

Is Pollution Causing Type 2 Diabetes and Obesity?

It sounds like Jerome Ruzzin is convinced it does. I put some thought into it last August and was skeptical—still am, but I’m keeping an open mind. Mr. Ruzzin has a review article published in 2012 at BMC Public Health (“Public health concern behind the exposure to persistent organic pollutants and the risk of metabolic diseases”). Here’s his summary:

The global prevalence of metabolic diseases like obesity and type 2 diabetes, and its colossal economic and social costs represent a major public health issue for our societies. There is now solid evidence demonstrating the contribution of POPs [persistent organic pollutants], at environmental levels, to metabolic disorders. Thus, human exposure to POPs might have, for decades, been sufficient and enough to participate to the epidemics of obesity and type 2 diabetes. Based on recent studies, the fundaments of current risk assessment of POPs, like “concept of additive effects” or “dioxins and dl-PCBs induced similar biological effects through AhR”, appear unlikely to predict the risk of metabolic diseases. Furthermore, POP regulation in food products should be harmonized and re-evaluated to better protect consumers. Neglecting the novel and emerging knowledge about the link between POPs and metabolic diseases will have significant health impacts for the general population and the next generations.

Read the whole enchilada.

Salmon is a good source of omega-3 fatty acids, but are they dangerously polluted?

Salmon are a good source of omega-3 fatty acids, but are they dangerously polluted?

The cold-water fatty fish I so often recommend to my patients could be hurting them. They are major reservoirs of food-based POPs.

Steve Parker, M.D.

Has Eating-Out Contributed to Overweight and Obesity?

So easy to over-eat!

So easy to over-eat!

The U.S. trend of increasing overweight and obesity started about 1970. I wonder if eating away from home is related to the trend. I found a USDA report with pertinent data from 1977 to 1995. It also has interesting info on snacking and total calories consumed. Some quotes:

“We define home and away-from-home foods based on where the foods are obtained, not where they are eaten. Food at home consists of foods purchased at a retail store, such as a grocery store, a convenience store, or a supermarket. Food away from home consists of foods obtained at various places other than retail stores (mainly food-service establishments).”

***

“Over the past two decades, the number of meals consumed has remained fairly stable at 2.6 to 2.7 per day. However, snacking has increased, from less than once a day in 1987-88 to 1.6 times per day in 1995. The increased popularity in dining out is evident as the proportion of meals away from home increased from 16 percent in 1977-78 to 29 percent in 1995, and the proportion of snacks away from home rose from 17 percent in 1977-78 to 22 percent in 1995. Overall, eating occasions (meals and snacks) away from home increased by more than two-thirds over the past two decades, from 16 percent of all eating occasions in 1977-78 to 27 percent in 1995.”

***

“Average caloric intake declined from 1,876 calories per person per day in 1977-78 to 1,807 calories per person per day in 1987-88, then rose steadily to 2,043 calories per person per day in 1995.”

***

“These numbers suggest that, when eating out, people either eat more or eat higher-calorie foods or both.”

Parker here. I’m well aware that these data points don’t prove that increased eating-out, increased snacking,  and increased total calorie consumption have caused our overweight and obesity problem. But they sure make you wonder, don’t they? None of these factors was on a recent list of potential causes of obesity.

If accurate, the increased calories alone could be the cause. Fast-food and other restaurants do all they possibly can to satisfy your cravings and earn your repeat business.

If you struggle with overweight, why not cut down on snacking and eating meals away from home?

Steve Parker, M.D.

Update January 23, 2013:

Here’s a pie chart I found with more current and detailed information from the U.S. government (h/t Yoni Freedhoff):

feb13_feature_guthrie_fig03

Ketogenic Diet Overview

We’re starting to see a resurgence of interest in ketogenic diets for weight loss and management, at least in the United States. Also called “very-low-carb diets,” ketogenic diets have been around for over a hundred years. A few writers in the vanguard recently are Jimmy Moore, Dr. Peter Attia, and Dr. Georgia Ede. Before them, Dr. Robert Atkins was a modern pioneer with his famous Atkins Diet and its Induction Phase.

What is a Ketogenic Diet?

There are many different programs but they tend to share certain characteristics. They restrict digestible carbohydrate consumption to 50 or fewer grams a day, sometimes under 20 grams. This totally eliminates or drastically reduces some foods, such as grains, beans, starchy vegetables (corn, potatoes, peas, etc), milk, and sugar. Nor can you have products made from these, such as bread, cookies, pies, cakes, potato and corn chips, and candy. You eat meat, eggs, fish, chicken, certain cheeses, nuts, low-carb vegetables (e.g., salad greens, broccoli, green beans, cauliflower), and oils. Total calorie consumption is not restricted; you count carb grams rather than calories. This is a radical change in eating for most people.

You’re may be wondering what “ketogenic” means. First, understand that your body gets nearly all its energy either from fats, or from carbohydrates like glucose and glycogen. In people eating normally, 60% of their energy at rest comes from fats. In a ketogenic diet, the carbohydrate content of the diet is so low that the body has to break down even more of its fat to supply energy needed by most tissues. Fat breakdown generates ketone bodies in the bloodstream. Hence, “ketogenic diet.” Some of the recent writers are using the phrase “nutritional ketosis” to summarize this metabolic state.

Ketogenic Versus Traditional Calorie-Restricted Dieting

Are there advantages to ketogenic diets for weight loss and management? Numerous recent studies have demonstrated superior weight-loss results with very-low-carb diets as compared to traditional calorie-restricted diets. Weight loss is often faster and more consistently in the range of one or two pounds (0.5 to 0.9 kg) a week. Very-low-carb dieters have less trouble with hunger. If you do get hungry, there’s always something you can eat. From a practical, day-to-day viewpoint, these diets can be easier to follow, with a bit less regimentation than calorie-restricted plans.

Ketogenic diets typically lower blood sugar levels, which is important for anyone with diabetes, prediabetes, and metabolic syndrome. We see higher levels of HDL cholesterol (the good kind), lower triglyceride levels, and a shift in LDL cholesterol to the “large fluffy” kind, all of which may reduce the risk of heart disease. Getting even further into the science weeds, very-low-carb diets reduce insulin levels in people who often have elevated levels (hyperinsulinemia), which may help reduce chronic diseases like type 2 diabetes, high blood pressure, some cancers, and coronary heart disease.  Clearly, ketogenic diets work well for a significant portion of the overweight population, but not for everybody.

Sounds great so far! So why aren’t very-low-carb diets used more often? Many dieters can’t live with the restrictions. Your body may rebel against the switch from a carbohydrate-based energy metabolism to one based on fats. Most of us live in a society or subculture in which carbohydrates are everywhere and they’re cheap; temptation is never-ending.

What Could Go Wrong on a Ketogenic Diet?

Very-low-carb ketogenic diets have been associated with headaches, bad breath, easy bruising, nausea, fatigue, aching, muscle cramps, constipation, and dizziness, among other symptoms.

“Induction flu” may occur around days two through five, consisting of achiness, easy fatigue, and low energy. Atkins dieters came up with the term. It usually clears up after a few days. Some people think of induction flu as a withdrawal syndrome from sugar or refined carbohydrate. My conception is that it’s simply an adjustment period for your body to switch from a carbohydrate-based energy system to one based on fat. Your body cells need time to rev up certain enzymes systems while mothballing other enzymes. To prevent or minimize induction flu, Drs. Stephen Phinney, Jeff Volek, and Eric Westman routinely recommend eating 1/2 tsp of table salt daily.

Very-low-carb ketogenic diets may have the potential to cause osteoporosis (thin, brittle bones), kidney stones, low blood pressure, constipation, gout, high uric acid in the blood, excessive loss of sodium and potassium in the urine, worsening of kidney disease, deficiency of calcium and vitamins A, B, C, and D, among other adverse effects. From a practical viewpoint, these are rarely seen, and many experts say they don’t occur in a well-designed ketogenic diet eaten by an essentially healthy person. I favor ketogenic diets designed by physicians or dietitians. In view of these potential adverse effects, however, it’s a good idea to run your ketogenic diet of choice by your personal physician before you get started. This is especially important if you have diabetes, chronic kidney or liver disease, or a history of gout, low blood pressure, or kidney stones.

Athletic individuals who perform vigorous exercise should expect a deterioration in performance levels during the first four weeks or so of any ketogenic very-low-carb diet. Again, the body needs that time to adjust to burning mostly fat for fuel rather than carbohydrate.

Competitive weightlifters or other anaerobic athletes (e.g., sprinters) may be hampered by the low muscle glycogen stores that accompany ketogenic diets. They may need more carbohydrates, perhaps 150 grams a day.

What’s Next After Losing Weight on a Ketogenic Diet?

A majority of folks eventually increase their carbohydrate consumption above 50 grams a day, which usually takes them out of nutritional ketosis. If they return to the typical 200-300 grams a day that most people eat, they’ll probably gain the lost weight back. Many have found, however, that they can go up to 70-100 grams and maintain at a happy weight. A well-designed program should give careful instructions on the transition out of ketosis and avoidance of regain.

To see a ketogenic diet I designed for my patients, visit:

http://diabeticmediterraneandiet.com/ketogenic-mediterranean-diet/

Steve Parker, M.D.

Steve Parker, M.D., is a leading medical expert on the Mediterranean diet and creator of the world’s first low-carb Mediterranean diet.  He has three decades’ experience practicing Internal Medicine and counseling on effective weight-loss strategies.  Dr. Parker is the author of “The Advanced Mediterranean Diet: Lose Weight, Feel Better, Live Longer (2nd Edition),“Conquer Diabetes and Prediabetes: The Low-Carb Mediterranean Diet, “ and “KMD: Ketogenic Mediterranean Diet.”

You’re Still at Risk Healthwise Even If You’re “Metabolically Healthy”

I'll eat my hat if this dude doesn't have metabolic syndrome

I’ll eat my hat if this dude doesn’t have metabolic syndrome

See details at MedPageToday.

Some studies suggest you can be healthy and long-lived while obese as long as you are “metabolically healthy.” That is, if you have normal blood pressure, LDL cholesterol, triglycerides, blood sugar, and waist circumference. A new meta-analysis finds that ain’t so: you’re still at higher risk for death or cardiovascular events if you’re obese and free of metabolic syndrome features.

“Our results do not support this concept of ‘benign obesity’ and demonstrate that there is no ‘healthy’ pattern of obesity,” Kramer and colleagues wrote. “Even within the same category of metabolic status (healthy or unhealthy) we show that certain cardiovascular risk factors (blood pressure, waist circumference, low high-density lipoprotein cholesterol level, insulin resistance) progressively increase from normal weight to overweight to obese.”

Click for the scientific journal abstract.

This report does not directly address the “fat but fit” concept, whereby you can counteract some of the adverse health effects of obesity by being fit. By fit, I mean regularly exercising and achieving a decent level of capacity and tolerance for physical activity. Fat but fit still holds.

Steve Parker, M.D.

Does Turning Your Heater Down Help You Lose Weight?

Dr. Stephan Guyenet thinks it might. (I’m skeptical.) It’s not so much central heat as it is failing to expose our bodies adequately to temperatures around 60° F (15.6° C) or lower on a regular basis. Here’s a human experiment Dr. G wrote about:

The second study went further, using a longer cold exposure protocol to investigate changes in fat mass among people with low brown fat activity at baseline (4).  Researchers exposed volunteers to 63 F (17 C) air for two hours a day over a six-week period; again I assume they were lightly clothed.  As in the previous study, they observed an increase in brown fat activity with cold training, and they found that calorie expenditure was higher when subjects were in the ‘cold’ air.  After six weeks of training, body fat mass had declined by about 5 percent.  This is despite the fact that all subjects were lean to begin with!

Read the rest.

Mount Humphries on the horizon is highest point in Arizona, 12,633 ft above sea level. High and cold.

Mount Humphries on the horizon is highest point in Arizona, 12,633 ft above sea level. High and cold.

I thought this study tied in with that one showing an inverse relationship between altitude and obesity. Environmental temperatures rise roughly 3° F with every 1,000 feet (305 meters). But the altitude study controlled for (accounted for) temperature, meaning that the temperature had nothing to do with the association.

Somebody’s probably already tried to link environmental temperatures—whether inside the house or out—to obesity rates. Let me know if you find it.

—Steve

Update:

A few minutes at Pubmed.gov revealed this 2013 abstract:

Objective: Raised ambient temperatures may result in a negative energy balance characterized by decreased food intake and raised energy expenditure. This study tested whether indoor temperatures above the thermoneutral zone for clothed humans (approx. 23 o C) were associated with a reduced body mass index (BMI). Design and Methods: Participants were 100,152 adults (≥ 16 years) drawn from 13 consecutive annual waves of the nationally representative Health Survey for England (1995 – 2007). Results: BMI levels of those residing in air temperatures above 23 o C were lower than those living in an ambient temperature of under 19 o C (b = -.233, SE =.053, p <.001), in analyses that adjusted for participant age, gender, social class, health and the month/year of assessment. Robustness tests showed that high indoor temperatures were associated with reduced BMI levels in winter and non-winter months and early (1995 – 2000) and later (2001 – 2007) survey waves. Including additional demographic, environmental, and health behavior variables did not diminish the link between high indoor temperatures and reduced BMI. Conclusions: Elevated ambient indoor temperatures are associated with low BMI levels. Further research is needed to establish the potential causal nature of this relationship.

And there’s this abstract, probably from the altitude study I mentioned:

http://www.ncbi.nlm.nih.gov/pubmed/23357956

“There was an approximately parabolic relationship between mean annual temperature and obesity, with maximum prevalence in counties with average temperatures near 18 °C [64.4° F].”

I don’t have the full article, but parabolic, to me in this context, probably means the obesity incidence was highest at 64.4° F, with lower obesity incidence both above and below 64.4°.

Of course, living in a particular environment doesn’t equate to exposing yourself to outdoor temperatures. But it makes sense that someone living in a cold environment will have more cold exposure than someone in a hot climate.

Perhaps 64.4° F is a sweet spot for efficient body temp regulation and energy partitioning. Living at temps significantly above or below that may cost you energy-wise: you expend extra calories maintaining a normal body temperature, tending to result in lower obesity incidence.

The Less Sugar, the More Overweight in a Scottish Population

Fanatic Cook Bix found a study showing an inverse relationship between sugar intake and body fat in a Scottish study. In other words, overweigh and obesity increased as sugar consumption fell. It’s not what I  had expected.  haven’t read the original report yet.

Gut Bacteria Affect Obesity and Leanness

Keep your fat germs away from me!

Keep your fat germs away from me!

From a Gina Kolata article at The New York Times:

The evidence is from a novel experiment involving mice and humans that is part of a growing fascination with gut bacteria and their role in health and diseases like irritable bowel syndrome and Crohn’s disease. In this case, the focus was on obesity. Researchers found pairs of human twins in which one was obese and the other lean. They transferred gut bacteria from these twins into mice and watched what happened. The mice with bacteria from fat twins grew fat; those that got bacteria from lean twins stayed lean.

Here’s the experiment write-up.

These findings may lead the way to new obesity treatments.