During a Q & A session on the low-carb cruise, someone asked Dr. Eric Westman if calories count. Of course calories count, Dr. Westman replied – but that doesn’t mean you need to count calories.

Yes, I know that may sound strange, but my own experience on this year’s cruise is a perfect example of what he’s talking about: I ate a lot, more than I eat at home, but didn’t gain an ounce. (Last year I lost a pound, but I figured that could be water weight.) Here’s what a typical day’s intake looked like for me during the seven-day cruise:

Breakfast: a big pile of scrambled eggs, three sausage links, four slices of bacon, four slices of Canadian bacon, coffee with cream.

Lunch: Greek salad with feta cheese and a big plate of tandoori chicken, tandoori beef and tandoori fish. The tandoori was oily and delicious.

Dinner: Usually two appetizers (cream soup, shrimp cocktail, stuffed mushrooms, salad, etc.), entrees (sometimes two) consisting of steak, lobster, pork chops or lamb, steamed vegetables with lots of butter, plus a cheese plate for dessert.

Late-night snack: two cheeseburger patties with grilled onions on four nights, pizza toppings on another night.

I also drank red wine every night, at least a few glasses, and more than a few on one evening. (Jimmy Moore told me he got an “I love you, Man” from me four times that night.)

Some people insist a low-carb diet is just low-calorie diet in disguise, and that certainly can be the case. Studies have shown that people who adopt low-carb diets often eat less spontaneously, even if they’re not told to restrict calories, and I believe that alone means something beneficial is going on. If you eat less without consciously counting calories, it means you’re not hungry. Diets that require you to go through life perpetually hungry are a prescription for failure.

But there’s no way my diet on the cruise was a low-calorie diet in disguise. It was a high-calorie diet, period. Ask anyone who sat at my table during dinner or any of the Swedes who joined me for late-night cheeseburger patties.

Two days before the cruise, I weighed myself at the gym: 190 pounds. Two days after the cruise, I weighed myself at the gym again: 190 pounds.

I mentioned in a post awhile back that my size 36 pants are a bit too loose these days, but size 34 pants are bit too tight, so I’m probably a size 35. (I peaked at size 40 pants several years ago but wore size 38 pants for most of my 30s and 40s.) A few days after returning home from the cruise, I slipped on some jeans and was disappointed that they were just a wee bit tight. Rats, I thought, maybe I did gain a bit on the cruise.

Nope. I looked at the tag and saw I was wearing a pair of size 34 jeans – and they were just barely tight. After I wore them for a couple of hours, they stretched a bit and fit just fine. Meanwhile, my size 36 jeans are noticeably loose. That’s after a week of eating like a king on the cruise.

So what’s going on here? Does my cruise experience mean calories don’t count? Did the excess calories disappear into thin air?

No, of course not. Calories don’t disappear. But my body found some way to use up those calories, so I stayed at the same weight despite eating more than usual. No laws of physics were violated in the process.

There’s been an ongoing debate about whether or not a ketogenic diet provides some kind of metabolic advantage that allows people to either eat more without gaining weight or lose weight without restricting calories as much as on other diets. I don’t know if there’s a true metabolic advantage or not, and I haven’t much cared one way or the other. If I can eat until I’m satisfied and still get a little leaner over time, that’s good enough for me, even if the weight loss is 100% due to unintentional calorie restriction.

People have sent me links to studies that supposedly disprove the existence of a metabolic advantage, but they were all studies of semi-starvation diets, somewhere in the 800-calorie-per-day range, with carbohydrate intake ranging from 20% to as high as 50%. The average weight loss was the same across the high-carb and low-carb groups. Well, here’s the trouble with those studies: At 800 calories per day, even 50% of calories from carbohydrates only works out to 100 grams per day. That’s a ketogenic diet. Comparing one semi-starvation ketogenic diet to another semi-starvation ketogenic diet doesn’t disprove that a ketogenic diet might provide a metabolic benefit in other circumstances.

If there is a true metabolic advantage (and that’s a big if) with a ketogenic diet, I suspect it shows up at higher calorie intakes. In one study I read, three groups of young men went on 1800-calorie diets for 9 weeks with protein held constant at 115 grams per day, while carbohydrate intake was set at 30 grams, 60 grams, or 104 grams. The 104-gram group lost 26 pounds on average, the 60-gram group lost 28 pounds, and the 30-gram group lost 35 pounds. A metabolic advantage? Maybe, but it was a small study and the researchers wrote that they didn’t track physical activity.

But so far we’re still talking about weight loss. I don’t care how many carbohydrates you do or don’t consume, you won’t lose weight without giving your body a reason to tap your stored body fat. Way back in the first Protein Power book, Drs. Mike and Mary Dan Eades made that clear: shedding body fat requires a calorie deficit. The point of a low-carb diet, as they explained, is to make it easier to tap your stored fat once you create that deficit. If you can’t tap your stored body fat, eating less will just create a fuel shortage at the cellular level, and your body will respond by slowing your metabolism, converting the protein in your muscles to glucose, or both. You’ll also be ravenously hungry.

In the same book, however, they wrote about the phenomenon that I experienced on the last two cruises: some people on low-carb diets seem to be resistant to gaining weight, even when they’re clearly eating more than they need. One patient complained to them that her weight hadn’t budged after several weeks on a low-carb diet. When they checked her food log, they ran the numbers and found that she was consuming around 4,000 calories per day. Of course she wasn’t losing weight. But strangely, she wasn’t gaining either. Perhaps that’s where an actual metabolic advantage shows up: as a resistance to gaining weight.

So out of curiosity, I emailed Dr. Mike Eades, Dr. Richard Feinman and Jonathan Bailor (author of The Smarter Science of Slim) about my cruise-ship overeating experience and asked for their comments. Here’s what they had to say:

Dr. Mike Eades

I’ve had many patients and readers who have had the same thing happen. They eat a ton of low-carb food and don’t lose weight…but neither do they gain. I think there is indeed a metabolic advantage that kicks in with these excess calories. I know some people claim to be able to gain huge amounts of weight eating strictly low-carb – and maybe they do – but that hasn’t been the experience in the case of the patients and readers I’ve dealt with.

In the overfeeding studies, subjects never gain as much as their caloric intake would predict, and this is even with high-carb foods. Obviously the body has a way to deal with excess calories, and I think whatever this mechanism is kicks in in spades when the overeating is basically very restricted in carbohydrate.

This is the kind of study Gary Taubes is trying to get funding for.

Dr. Richard Feinman

I got into this field almost ten years ago over thermodynamics, which is frequently brought up. Like most people who have actually studied the subject, I am quite modest about my own understanding but I could see that the nutrition world needed help.

I knew I was on the right track when my brother said that he had been at a conference where they had a buffet and he had pigged out on lobster and roast beef but had not gained any weight. That is what a metabolic advantage is. It’s more striking if you are overweight, of course.

As for why it is not apparent when you are at home is unknown — the key thing is that it can happen. If we could get people to focus on it — my gift to the nutrition world was under-appreciated — then we could find out exactly what the important parameters are. Two things we know for sure: 1. nobody has ever been on any cruise diet that was a “low-calorie diet in disguise,” and 2. nobody has ever said: “I don’t understand. I was at this conference and they had a buffet and I really pigged out on pasta but when I got home I hadn’t gained any weight.”

(Actually, I have noticed the same phenomenon at home — I just don’t eat cruise-sized meals at home. But if we go out for dinner and I chow down on steak, lobster, shrimp, etc., it never seems to put any weight on me.)

Jonathan Bailor (quoting from his book)

Let’s return to the idea of a clog. If you pour more water into an unclogged sink, then it will drain more water. You will only see water build up if you put more water into a clogged sink. Our fat metabolism system works the same way. If you put more food in an unclogged fat metabolism system, then it will burn more calories. Body fat will build up only if you put more food into a clogged fat metabolism system.

In a Mayo Clinic study, researchers fed people 1,000 extra calories per day for eight weeks. A thousand extra calories per day for eight weeks totals 56,000 extra calories. Everyone gained sixteen pounds—56,000 calories worth—of body fat, right?

Nope.

Nobody gained sixteen pounds. The most anyone gained was a little over half that. The least anyone gained was basically nothing—less than a pound. How could that be true? People are eating 56,000 extra calories and gaining basically no body fat? How can 56,000 extra calories add up to nothing?

That’s because extra calories don’t have to turn into body fat. They could turn into heat. They could be burned off automatically. Researcher D.M. Lyon in the medical journal QJM reported: “Food in excess of immediate requirements…can easily be disposed of, being burnt up and dissipated as heat. Did this capacity not exist, obesity would be almost universal.”

Eating more and gaining less is possible because an unclogged fat metabolism system has all sorts of underappreciated ways to process excess calories other than storing them as body fat. In the Mayo Clinic study, researchers measured three of them:

1. Increase the amount of calories burned daily.

2. Increase the amount of calories burned digesting food.

3. Increase the amount calories burned via unconscious activity.

Bailor included a chart of data from the Mayo Clinic study showing that the increase in calories expended from the three factors listed above added up to more than 1,000 calories per day in some people. In other words, their bodies reacted to 1,000 extra calories by burning somewhat more than that.

Now, I’m pretty sure if I kept up my cruise-ship diet for weeks on end, I could overwhelm my metabolism and start gaining weight at some point. I don’t plan to find out. I’m happy enough knowing I can eat like a king for a week and come home weighing no more than when I left. Considering that a cruise director once told me the average cruise passenger gains a pound per day, no change is definitely a victory.

Speaking of the cruise, Jimmy Moore managed to get me an audio file of the roast that he stripped from his iPhone video. There’s still some room echo, but not as much as on my camera. I’ll get it all put together and post it over the weekend.