Considering that study lists burgers (with bun), pizza and chips as part of the "high fat/low carb" diet, I'd say it doesn't say much of anything about paleo.

When the study says "low carb", they mean marginally lower carb than SAD (or SSD). Like, going from 40% to 35% of calories. This isn't a true low carb diet like we would consider it.

As John Turner said, and not to sound anti-science, because I'm not, but large scale nutrition studies like this seem to have so many flaws that they do more harm through spreading bad information than they do good through telling us anything about how we should eat.

Finally, for a study like this, I could care less about the participants' cholesterol rates. Why don't they report on the mortality rates and causes of death? Why obscure the information we really want by filtering it through one more link of causation that needs to be made?

The best thing to tell them is that the diets were neither low-carb nor Paleo.

The macronutrient breakdown was roughly 40% fat, 14% protein, and 46% carbohydrate.

From the full text:

Changing intake patterns for fat and carbohydrate 1986 to 2010 In 1986, mean reported fat intake, adjusted for age and BMI, was 39.2% of the men’s total reported energy intake (E%). Carbohydrates made up 45.9 E% and protein 13.6 E%. For women the corresponding levels were 35.5 E%, 49.2 E% and 14.3 E% for fat, carbohydrates and protein, respectively, in the same year (Figrue 2). From 1986 to 2010 two significant trend breaks in reported fat intake were identified for both men and women. A decrease from 1986 to 1992 resulted in a reduction of reported fat intake by 2.9 E% in men and 4.4 E% in women. These levels stayed largely stable until 2002–2004, and thereafter a significant increase occurred, and reported fat intake reached levels above those in 1986. Thus, in 2010 men got 39.9% and women 37.7% of their reported total energy intake from fat. The trends were similar in 10-year age groups (Additional file 1: Figure S1). Intake of saturated fat correlated highly with total fat, i.e. Spearman correlation coefficients were 0.86 for men and 0.87 for women. Reported intake of saturated fat followed a similar pattern as total fat, and the correlation coefficients were virtually identical each year (data not shown). In the same period reciprocal trend shifts were seen for reported carbohydrate intake (Figure 2). The fraction of energy originating from protein was virtually unchanged over the 25-year period, i.e. a slight increase by 0.9 E% was seen for both men and women but no significant trend break was identified (Figure 2).

Also, the foods associated with fat consumption were:

Time trends for foods associated with high fat intake Fats used for spreading on bread and cooking, dairy products, oil for salad dressing or cooking, various types of meats and sausages as main dish or on sandwiches, pizza, deep- fried potato chips (French fries), and non-sweet snacks (including potato and maize crisps (chips), cheese-flavoured puffed products, popcorn, and peanuts) were identified to be associated with high fat intake (fatE%)

Here's a link to the provisional PDF: http://www.nutritionj.com/content/pdf/1475-2891-11-40.pdf

What should you say to them about it?

I dunno. What do you say to them about this:

1. "My over-weight, high-carb, low-fat eating coworkers." Have you ever pointed out that their Lean Cuisines don't seem to be working?

2. I'm trying to pull up the full pdf of this study, but it doesn't want to load at the moment. But the first thing to note is, it looks like the Atlantic article is purely correlational. (And we know the difference between correlation and causation, right kids?) Also, the abstract says it was based on "self-reported food and nutrient intake." Giving people food recall questionnaires is, in terms of clinical research, notoriously shaky, shady, and unreliable. (Heheh...this is why people are sometimes encouraged to do a food journal when they're not getting the results they want with Paleo. We forget that the "one little piece" we grab of something, oh, 4 or 5 times a day, adds up! You think these people who self-reported as following a low-carb, high-fat diet are going to own up to all the times they slipped, cheated, or what-have-you? "I'm totally low carb, except for my friend's wedding...oh, and the weeklong cruise I went on...oh, and the Christmas party...and Easter...and...)

And since I can't bring up the full pdf, I can't determine the quality of this study. Was it even really a "low carb diet?" Medical "research" literature is full of studies on "low carb diets" that compared, say, a standard diet of about 60% calories from carbs to the "low carb diet" of 45 or 40% carbs. That. Is. Not. Low. Carb. So when you add back lots of fat on top of 45% carbs, NO, of COURSE your weight and blood lipids probably won't improve. Jeez. (Especially if you're sedentary!)

I'm sorry -- I'd like to say more, but really, without being able to read the actual study, we have no idea if the research really says what The Atlantic tells us it does. (I'm getting an MS in nutrition and am in a class called "Evidence Based Nutrition" right now. This is all we do -- evaluate the legitimacy of studies, and lemme tell ya, most of them are very good -- for lining your birdcage, that is!!)

I guess this matters if you believe the cholesterol hypothesis. Not sure what to tell your co-workers if they think cholesterol levels are linked to heart disease. You would have to get around that if they're going to get their heads around this.

You can probably find a study that shows more or less anything. Who cares about one more?

I feel better than ever eating this way. I don't need anymore studies to make me feel good or bad about how I eat.

"What do you think of this study damning the way you eat?"

"I dunno, how do you suggest I eat?"

"Well, I eat oatmeal every morning, lean cuisine for lunch, and I have pasta for dinner with lots of red wine!"

"Yeah? And how's that working out for you?"

(Walk away before response is given)

That's how I'd handle it, but I'm a prick.

Alternate answer:

You could get some info from the Weston Price Foundation website that would explain low cholesterol levels have been linked with violence, aggression, suicide, and violent death. (Plus greater mortality rates from cancer.) Low cholesterol ain't all it's cracked up to be.

Don't worry, guys. Stabby took care of it in the comments. All is well in the world again.

As Heather already mentioned, it depends on if you believe high cholesterol is dangerous or not. I don't have time to review the full report, but the linked article does not indicate if the increased levels were in HDL, LDL or both. If HDL increased and LDL lowered or stayed the same, I'd argue the LCHF diet may have, in fact, been healthier.

Other things to consider are that these types of studies usually do not differentiate protein/fat sources, so you can assume most are conventional (non grass fed) and thus higher in Omega6 levels than what paleo camps advocate. They may also be using lower quality fats/proteins (again I don't have time for a full study review).

In the end, you just have to read up on things, form your own opinion, and follow it blindly. It's what humans have been doing since the dawn of time, and it's gotten us this far ;)

Witty comeback. Hmmmmm...

The database was created because of high incidence of CV problems in Swedish men. To no one's great surprise total cholesterol went up when the population started eating more animal fat. People on Paleohacks report the same thing every day.

My favorite CV risk tool is Framingham. Increasing TC has a slight effect in increasing CV risk, but nothing like high blood pressure and low HDL do. So factors which improve those two are the ones really worth worrying about, and paleo lifestyle improves both.

So at the end my witty comeback is

"What are you doing to reduce YOUR risk of stroke or heart attack?"

If they're obese I'd be interested in whether their response is medication...

Here is a near perfect response..

http://www.drbriffa.com/2012/06/12/shocking-swedish-science/

You can also mention that many hunter-gatherer groups have blood cholesterol levels hovering around 260, and they have none of the diseases of modern civilization.

The criteria for "high cholesterol" are arbitrary and suited to help one entity, and one entity alone—drug companies. It is a poorly understood test and we're not even sure what to do with the results. Results that, by the way, vary widely depending on the day and time.

You could also arm yourself with the list of side effects from cholesterol meds: memory problems, diabetes, erectile dysfunction, etc.

But take heart, the fact that these people are grasping at straws means they have nothing of any real substance to nail you with.

"Please give me some witty come-backs when my over-weight, high-carb, low-fat eating coworkers smugly ask me about this latest study"

They are obese because they eat too much and move too little. I also pretty much guarantee they are not eating a low fat diet. Or do you follow them around and watch what they eat all day? I'm going to guess that they are just the same as my coworkers and eat baked goods like muffins, scones, and donuts, etc. I bet chips aren't unheard of either. Oh, they probably also eat cheese. High carb, sure, but high everything else as well.

PS I bet they hate you.

Witty comeback, are you 15? Just let it be. Know what works for you, keep doing it...

I have higher cholesterol, my HDLs are killing me!

"On average, Swedes who switched from a lower fat diet to a higher fat/lower carbohydrate diet saw their blood cholesterol creep up"

This just proves that low carb-high fats diets are healthier (from a cholesterol perspective, at least) (if you don't believe in the whole cholesterol-will-kill-you B.S).

"despite an increased use of cholesterol lowering medication."

Low carb-high fat diets even conquer toxic chemicals, apparently. What more can you expect? :)

Some good responses to this at LessWrong.

HDL is good. LDL large fluffy is neutral. LDL small dense is bad. Which cholesterol went up?