Tag Archives: induction phase

For Heart’s Sake, Should You Avoid Red Meat in a Low-Carb Diet?

Low carbohydrate diets tend to contain disproportionate amounts of fat from animal sources.  Red meat has long been vilified as a major source of saturated fat that some experts believe cause hardening-of-the-arteries (atherosclerosis) via elevations in LDL cholesterol.  Others disagree.  Poultry, fish ,and shellfish generally have lower amounts of saturated fat than red meat.  Would a low-carb diet with a predominance of poultry, fish, and shellfish lead to a more advantageous cholesterol profile?

A 2007 report from U.S. researchers found no lipid advantage to the poultry/fish/shellfish model.    In fact, despite high cholesterol and fat intakes, neither diet caused a significant change in total, HDL, or LDL cholesterol levels.  Triglycerides fell in both groups, but to a statistically significant degree only on the poultry/fish/shellfish group.

Fun Fact:  Did you know that four of every 10 women in the U.S. are trying to lose weight?  The figure for men is one in three.  

Methodology

Researchers in Minnesota and Iowa enrolled 18 subjects (6 males, 12 females) between the ages of 30 and 50 who wanted to lose weight.  Average body mass index was 31.7, which is mildly obese.  The were encouraged to eat an Atkins-style ketogenic diet with a maximum of 20 g carbs/day, providing 1,487 total daily calories, with 7% of calories from carbohydrate, 43% from protein, and 50% from fat.  This included two or three cups of salad greens and low-carb vegetables.  Three ounces of cheese daily was allowed.  Subjects were randomly assigned to eat either red meat or poultry/fish/shellfish.  Dietary intervention lasted 28 days.

[This is very similar to Atkins Induction Phase, although Atkins does not limit total calories.  The researchers did not say why they wanted to limit total calories.] 

Data were not used from six subjects for good reasons (see article).  So final data analysis included only 12 subjects.

Results

Both groups lost the same amount of weight: about 5.5 kg (12 pounds) over 28 days.

Average carbohydrate intake was about the same for both groups: 55 g/day.

Average total daily caloric intake was about the same for both groups: 1,380.

The poultry/fish/shellfish group ate 630 mg cholesterol daily, twice as much as the other group.  [Eggs and shrimp were popular.]

The difference in intake of saturated fat approached, but did not reach, statistical significance (32 g/day in the red meat group vs 25 g).

Neither diet caused a significant change in total, HDL, or LDL cholesterol levels.  Triglycerides fell in both groups, but to a statistically significant degree only on the poultry/fish/shellfish group.

Urine ketones at or above 5 mg/dl were detected on 75% of all dipstick tests.

My Comments

I’m skeptical about the accuracy of the calorie counts.  Most people eating Atkins-style take in about 1,800 cals/day.  The preponderance of females, however, may explain the unusually low average caloric intake.  They didn’t follow their carb restriction very closely, did they?  These were free-living subjects not locked in a metabolic ward.

The researchers note that the allowance of cheese in both groups may have sabotaged their efforts for a clear delineation of higher versus lower saturated fat groups. 

HDL cholesterol usually rises significantly on low-carb diets.  Lack of that here may just be a statistical aberration.

This is such a small study that it’s impossible to draw firm conclusions.  Nevertheless, if someone is losing weight on a low-carb diet, it may not matter much from a lipid viewpoint whether they eat a predominance of meat or a predominance of poultry, fish, and shellfish.  The study at hand cannot address the long-term consequences of such a choice.

Steve Parker, M.D.

Reference:  Cassady, Bridget, et al.  Effects of low carbohydrate diets high in red meats or poultry, fish and shellfish on plasma lipids and weight lossNutrition & Metabolism, 4:23   doi: 10.1186/1743-7075-4-23   Published October 31, 2007

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Filed under Carbohydrate, Fish, ketogenic diet, Overweight and Obesity

My Ketogenic Mediterranean Diet: Day 23

CB104470Weight: 161 lb

Transgressions: none

Exercise: 60 minutes shovelling horse poo and picking up rocks from a new corral

Comments

I followed Dr. Atkins New Diet Revolution for 10 weeks in 2003.  When my daughter was 3-years-old, I realized that my exercise habit—six hours a week either at a gym or running—had been interfering with my family time and helping out around the house.  So I quit exercising for 3–4 years and, therefore, gained some weight.  In 2003, my Atkins starting weight was 178 lb, waist 37 inches.  Goal weight was 162-165.  I lost 11 pounds on Atkins.  Towards the end I was bored and increasingly noncompliant.  Here are my 2003 verbatim notes summarizing my experience with Atkins:

Lost 10 lbs [4.55 kg] over first 5 weeks, ½ of that in the first 2 weeks.  I have not exercised nearly as much as he recommended.  Have not suffered much hunger or sense of deprivation.  No wt change in last 6 weeks, coinciding with poor exercise compliance (may or may not be related).  Note that I really don’t have much wt to lose at this point, just a cosmetic amount.  At some point, even if fully compliant with Atkins, wouldn’t wt loss stop in everyone?  I have no idea how may calories I am eating now.  With wt stable, will assume it is around 2000-2400 cal/day.  Ten years ago when I was exercising religiously, my wt-maintaining intake was 2400 cal.  Probably closer to 2000 now in view of aging and sedentariness.  Over the last 6 weeks of stable wt, however, I was mostly compliant with his induction-phase food prescription.  To lose wt now I probably need to exercise more and count actual calories.  Even took his recommended Essential Oils supplement (2/day) and Basic 3 vitamin supplement (2 instead of 3/day).  He has convinced me I am a carbaholic.  Sugars and refined carbs are empty calories that don’t provide much except energy, which in excessive amounts is stored as fat.  But I cannot yet abandon the dogma that saturated fats (e.g., red meat) can be harmful to circulation over the long run.  And his carb restriction would keep me from eating adequate beneficial vegetables.  If I want to eat sweets and refined carbs, I will have to exercise more and/or give up fats, vegetables, or proteins.  Atkins makes a lot of sense for obese people who love carbs and overeat them.  I also like the rapid results of induction phase.  I admire the simplicity of the induction phase.  Thereafter, the “Ongoing Weight Loss” and “Lifetime Maintenance” phases do require counting carbs.  The latter phase, for me, would allow 40-60 gm/day, unless I were a vigorous exerciser (then 90+ gm).  A serving of apple pie has 58 gm.

Now it’s six years later and I’m much more willing to reconsider that dogma that saturated fats cause impaired circulation (atherosclerosis).  But I still think that fruits, vegetables, whole grains, and legumes are healthy for many people.

-Steve

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Filed under My KMD Experience