Low carbohydrate diets are often criticized for being high in fat, particularly saturated fat, which is widely believed to raise cholesterol levels and increase risk for heart disease, despite recent  and older studies demonstrating that saturated fat is not to blame. However, many lipidologists believe that LDL particle number (lower number is better) and pattern (larger size is better) do correlate with heart disease risk.

My total, HDL, and LDL cholesterol have always been on the high side, even back in 2007 when I was a pesco-vegetarian who threw out egg yolks rather than eating them. The only time my LDL was in the “optimal” range (less than 100)  was the year I ate a vegan diet. However, I was also very hungry and sick a lot that year.

Recently, someone commented on another blog that “Every low-carb Paleo blogger has nightmarish cholesterol levels," or something very similar.  That’s a pretty broad generalization and one I don’t agree with. In many (most?) cases, elevated cholesterol levels are due to something other than diet. And are moderately elevated cholesterol levels always bad anyway?  From all the research I've seen, it's inflammation that appears to be at the root of heart disease. In addition,  low cholesterol levels have been linked to depression, poor memory, and other health issues. 

But I was still curious to see what my lipid numbers are like now, 11 months after beginning a very-low-carb, high-
fat diet that includes a fairly high percentage of saturated fat. I decided to order an NMR Lipoprofile test so I could get information about particle numbers, size, and pattern, which I've never had measured before, since I believe this is more important than just looking at LDL and HDL.

My results:

LDL Particle Number

LDL-P:    1174                    Reference range:             Moderate 1000-1299 
                                                                                     Borderline High 1300-1599
                                                                                     High >1600
 
Lipids

LDL-C:    124                      Reference range:           Above optimal 100-129
                                                                                    Borderline 130-159
                                                                                    High >160

HDL-C:  97                         Reference range >40

Total cholesterol:226    Reference range   <200

Triglycerides:   24           Reference range  <150

LDL and HDL particles

HDL- P(total):  43.8        Reference range >30.5

Small LDL-P:  103            Reference range  <527

LDL size:    21.7                  Reference range  20.6-23.0 (Pattern A, Low Cardiovascular Disease Risk)

Insulin resistance score

LP-IR score:   1                   Reference range  <45


Honestly, these numbers are better than I’d expected. My HDL has always been good, around 65-70, but it’s increased significantly, while my LDL-C has actually gone down a bit.  The particle size and numbers are also very good, as are the triglycerides.  I guess I shouldn't really be too surprised given research suggesting that a low-carb-high fat diet results in a less atherogenic lipid profile.

My results occurred nearly a year after eating eggs, butter, cream, cheese, and/or coconut oil every single day. Did I also eat a lot of monounsaturated fats in the form of nuts, olives, and avocado on a daily basis and omega-3 fats in fish several times a week?  Absolutely -- I eat a lot of all types of fat.  But I don’t think the saturated fat has done me any harm; on the contrary, I’ve written before about the benefits of many saturated fats. And limiting my carbs to less than 50 grams a day has resulted in finally normalizing my post-meal blood sugar, which I was unable to do at a moderate low-carb level of 80-100 grams.  My weight remains 125 pounds, give or take a pound.

So what do I eat? Here’s yesterday's intake and nutrient analysis courtesy of FitDay.com:

Breakfast:

4 oz sardines
3 cups spinach with ½ tsp sea salt cooked in 2 tsp coconut oil
1 cup blackberries with 1 oz sour cream and 1/3 cup chopped pecans
Green tea

Lunch:
1 sliced red bell pepper with Greek yogurt-guacamole dip (1/2 cup 2% Greek yogurt mixed with 2/3 cup guacamole)
Chia seed cocoa pudding (1 oz chia seed mixed with ½ cup water, 1 Tbsp cocoa powder, ½ tsp sea salt, ½ tsp cinnamon)
Vanilla hazelnut herb tea with 1 tsp half-and-half

Dinner:

Filet Oscar:  6 oz beef filet, 2 oz  crab, 2 Tbsp Bearnaise sauce, 1/2 cup each pea pods and summer squash  (pictured above) 
Water


Calories: 1700

Fat: 117 grams (62%)
Saturated: 33 grams
Polyunsaturated fatty acids(PUFA): 24 grams 
Monounsaturated fatty acids (MUFA): 60  grams 

Protein:  97 grams (23%)

Carbohydrates: 68 grams (16%)
Dietary fiber: 33 grams
Effective carbs: 35-51  grams (There are different schools of thought on how to count fiber. If subtracting all fiber from carbohydrate grams, effective carbs are 35 grams; if subtracting half the fiber grams, effective carbs are 51 grams) 

This is pretty typical intake for me in terms of macronutrient percentage, fiber, and calories. The majority of my fat intake always comes from MUFA and saturated fat, and most of the PUFAs are the omega-3 fatty acids found in seafood.

So I'm having great results all around on a low-carb, high-fat, whole foods diet. Everyone is different, of course.  I'm not arguing that some people have reported increases in LDL cholesterol after switching to a low-carbohydrate diet, although it seems to occur more often in the initial stages, particularly with folks who lose weight rapidly. But the oft-repeated message that a LCHF approach automatically increases cholesterol and risk for heart disease is not borne out by the research, my  n=1 results, and those of many others. 

Short post today on a new study suggesting that restricting carbohydrates in women with gestational diabetes mellitus (GDM) does not reduce their chances of needing insulin to control blood sugar during pregnancy.  Spanish researchers randomly assigned 152 women with GDM to a control diet or a "low carbohydrate" diet. Each of the diets contained at least 1800 calories. The control diet contained 55% of calories from carbohydrate. And the "low carbohydrate" diet? It specified 40% of calories as carbs, or at least 180 grams. Definitely not low-carb, and significantly more than most  of these women need, given the increased insulin resistance that is the hallmark of GDM. In addition, compliance was measured with three-day food records kept by the participants in their own homes rather than in a metabolic ward or other controlled setting where the amount of carbs actually consumed could be accurately assessed.  The women's food records indicated they consumed  between 155-191 grams of carbs daily; however, it's generally accepted that most people tend to underreport  the amount of food they eat.  The researchers concluded that a low-carbohydrate diet does not reduce insulin needs, but this is misleading  given that this diet contained considerably more carbs than the women should have been advised to eat. 

I've read other studies looking at similar "low carbohydrate" diets that actually weren't low enough to be therapeutic.  Part of the problem is that there's no universally accepted definition of that term, but in my opinion,  up to 190 grams of carbohydrate daily really seems like a stretch. Had these women been prescribed a diet containing less than 100 grams instead,  I'm fairly confident the number  requiring insulin would have been much lower than those following the control diet. I suspect they would have also had an easier time maintaining a healthy rate of weight gain during their pregnancies.

Unfortunately, given that the media often only report the "conclusions" in research abstracts, the take-home message will be that carb restriction doesn't decrease the need for insulin in GDM, so there's no reason to try it. And that's a shame, because we know that decreasing carbohydrates does lower insulin requirements, provided that the amount consumed is low enough to keep blood sugar at a healthy level.  40% of caloric intake clearly exceeds that limit.

References
 1. Morena-Castilla C, et al. Low-carbohydrate diet for the treatment of gestational diabetes: a randomized controlled trial. Diabetes Care. e-published ahead of print April 5, 2013 do1:30.2337/dc12-2714