Nutrition/Weight Loss

A Cautionary Tale About Not Eating Enough Fat

Eat Fat or ElseAs much as I hate to admit it, my initial success with low carb eating was through The South Beach Diet. I stuck with it through the induction phase, guided by my wife who had read the book. On my way out the door to work one morning she surprised me with, “I’m starting The South Beach Diet today. You in?” What was I supposed to say? “No, I’ll continue to eat McDonalds and Wendy’s every day in front of you.” Of course not. That’s not how I roll. So I gave it a shot, even though I wasn’t very motivated at first. Boy did that motivation level change quickly.

After the first day, I dropped 2 pounds. I couldn’t believe it. I ate a ton of food that day. Lots of foods containing saturated fat. Then the next day I lost another pound. And that pattern continued for 2 weeks. During those 2 weeks, while I don’t recall the exact number of pounds lost, it was somewhere between 7 and 10. I was amazed. Of course, I was also, as it turned out, needlessly worried that I would keel over from a heart attack, as the ‘Healthy Whole Grains’ industry, USDA, and Vegans/Vegetarians would love us all to believe. While I’ll focus on this in another post, I assure you that a low carb diet actually results in better cholesterol levels, reduced triglyceride level, etc. All good. Tests don’t lie. And empirical research doesn’t either. Unfortunately, according to Taubes’ Why We Get Fat, the one low carb diet plan that doesn’t result in the heart health is The South Beach Diet, amazingly enough. Why? I presume because The South Beach author is playing both sides of the fence: his diet is both low fat AND low carb. And that’s a long-term recipe for failure.

Flash forward to five months after starting my low carb journey. I had long abandoned, soon after ‘induction’, The South Beach Diet. I’m not one for the rigidity of these diet books. And, after researching on my own the information on low carb diets, I knew I no longer needed to bother with any ‘diet’ plan. Just eat as few carbs as possible and I would lose weight. And I did. And during this time, as I proceeded to lose approximately 40 pounds in 5 months, I also noticed that my energy level increased on an almost daily basis. I felt wonderful. Had so much more energy to play with my kids, get household chores done, etc. And then it hit me: I should channel this energy into exercising/working out, figuring it would accelerate my weight loss. As I’ve reported already, in hindsight it had the reverse effect and actually decelerated my weight loss. 

So I join my local health club and proceed to jump on the treadmill. I started jogging and was actually able to do it. I was never able to run for more than a minute in my life, yet here I was, sometimes hitting eight minute stretches without stopping. It was so exhilarating. Elliptical trainer was cool too. I was kicking ass, thinking within a few months I was gonna look like a million bucks. The health club I joined offers two free personal training sessions with a membership. I of course took advantage of it. The personal trainer urged me to start weight lifting two days a week, which I agreed was important (and still do), and to also do cardio on most days. I started lifting weights and continuing on with my cardio workouts.

Around this same time, my wife and I booked a 7-night, all-inclusive vacation at this place. Needless to say, I was a bit worried about going to Mexico for a week and being presented with free all I could eat room service, buffets, and alcohol. So, I decided to really focus on my eating. Up until then, I was eating as much as I wanted, whenever I wanted. I just avoided carbohydrates whenever possible, aside from those in most vegetables. So I started counting calories, reducing my fat intake, etc. I knew better. I read the research. But I ignored it.

Two weeks into my newly prescribed fitness routine I showed up at the gym and hit the proverbial wall. I was so lethargic that I just could barely make it through a weak workout. So I went home and took a few days off from the gym. I noticed I was lightheaded and dizzy. And just overall felt like crap. Lethargic. And a constant light, ‘dull’ headache. After a few days of these symptoms I started to worry quite a bit. In fact, I was convinced I had a tumor or something drastic. Of course, there was no way I was going to go to the doctor before vacation, as I figured I didn’t want to know if I was gonna die until after the vacation was over. Heck, I paid a lot of money for that vacation and I didn’t want to screw it up : )

Iberostar Tucan
Iberostar Tucan in Mexico

So we went on vacation. I overate, but they had plenty of meats, fish, eggs, etc., so I only gained a few pounds, and that was likely from the deserts and alcohol. I worked out a few times at the resort but, again, I felt dizzy and lightheaded pretty much the entire week. It put a damper on things. Add to that my son was sick as a dog and it was a tough week. I still had fun though swimming in the pool and hanging out with the ‘Star Friends’ ( a bunch of young folks paid to perform stunts, crack jokes, and run activities for the guests).

Star Friends
Star Friends

When I got back from vacation, I went to my doctor and told him my symptoms. He ran blood tests, checked blood pressure, etc. When the test results came back he raved about my improvement in cholesterol levels/triglycerides. Said I was in great health and nothing was wrong with me. I still had headaches, lightheadedness, dizzyness, and was starting to get even more worried. So worried that I thought maybe I was wrong this entire time, that I needed to eat carbohydrates after all. But I insisted on sticking it out and not eating that crap again, as I knew I felt so much better, even with the headaches and lightheadedness, than I did before I began a low carb lifestyle.

Approximately two months of this and I am almost ready to give up. I scoured the internet looking for answers and got all kinds of dumb advice that led me nowhere, like:

  • “Your magnesium levels are too low! Get a supplement!”
  • “Your potassium levels are too low! Buy some “No Salt” and start using it, and eat bananas.”
  • “You’re vitamin D deficient! Get a supplement!”
  • “What do you mean you aren’t taking <insert some other needless supplement here>?!? You better start!”
  • “Sounds to me like you’re iron deficient!”

Mind you, these recommendations were from people on low carb forums, who you think would know better. They didn’t. I tried them all to no avail. So I called my doctor back and told him I was still experiencing the symptoms, and I needed him to figure this out.

Then, that afternoon, while waiting for a call back from my doctor, it hit me:

I remembered that I had felt these same symptoms back during induction for a couple of days, while doing The South Beach Diet, and recalled that it was due to not eating enough fat to fuel my body.

I ran to the grocery store (in my car) and proceeded to buy a bunch of high-fat stuff: pepperoni, nuts, cheese, etc. In the car on the way home I started eating it like I hadn’t eaten in days. Within 3 hours I felt great again. No more lightheadedness, no more dizzyness, no more headaches. I’ve felt wonderful ever since, with the occasional ‘sluggish’ day here or there (which is still way better than a ‘good’ day prior to my going low carb).

Lesson here? Eat fat. Dietary fat does not equate to fat in your body. Once you ‘flip the metabolic switch’ on a low carb diet, fat is your body’s primary energy source. So eat plenty of it….or else. I severely limited what should have been a much more enjoyable summer due to not eating enough fat. I knew better. Just fell back into the old, wrong, paradigm.

I wonder: had I not started working out, would I have ever had these symptoms? I guess I’ll never know…



5 replies on “A Cautionary Tale About Not Eating Enough Fat”

Now I am wondering if that might be my problem as well. I’ve been low carbing for over three years and have kept the total daily net carbs at 20-22. Lately I have not had much of an appetite and have eaten far fewer carbs, sometimes less than 10-15 a day. [Low carbing really works as an appetite suppressant!]
But I have also experienced the same symptoms you wrote about, lightheadedness, mild headaches, slight dizziness, etc. Think I will pick up a bottle of coconut oil and start consuming a tablespoon or two everyday and see if that helps.


Definitely try loading up on the fat for a few days. In my case, I felt better just within a few hours, and then within a couple of days I was back to feeling great. I just wasn’t eating enough fat, and I think when I started working out that’s when what energy I was consuming/had in my body to burn (fat) was quickly depleted.

If I were you, I would eat more than just an extra couple of teaspoons of coconut oil. I would eat a lot of fat for a few days and see what happens. Theoretically, it shouldn’t cause any weight gain, so no reason not to try it and see if that is what is causing your symptoms.


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