What to do about low energy on low carb?


What to do about low energy on low carb? If calorie does not matter, what happens with excess fat that we take in? And what to do if your acid reflux gets worse on low carb?

Get the answers in this week’s Q&A with Dr. Andreas Eenfeldt:

What to do about low energy on low carb?

I have been eating low carb (under 40 net grams) for a few weeks now. Recently I have been experienced a real slump in energy levels mid-afternoon… The sleepiness really kicks in if I stop moving around. I am tracking my macros so I definitely am not increasing my carb intake and am having required amounts of protein. Can you offer any explanations/advice? Thank you for your time.


Try adding salt and fluid, e.g. a cup of bouillon 1-2 times a day.

Andreas Eenfeldt

If calories don’t matter, what happens with excess fat that we take in?

We know that excess of carbohydrates is stored as a fat. Some experiments show that after a period of excess calories on a high-fat diet there is no significant weight gain. How does the body use the rest of energy from the extra fat?


Fat is burned for fuel. It’s hard to overeat on a low-carb diet, as the satiety effect is so strong. As long as you only eat when you’re hungry, most people tend to not want to overeat on low carb.

Andreas Eenfeldt


Every time I start LCHF, I get acid reflux!

I’m desperate to do this diet and see it through, totally on board, but every time I start, by day 5, I’m having acid reflux/burbing symptoms, which are painful.

I’m at my wits end trying to switch things round every time to stop this from happening. I have had IBS in the past and know lots of dairy can be a trigger, but I’m trying not to consume that. LCHF seems to help other people’s acid – why is it making mine worse? What can I do please?


Hi F,

Most people improve long term on LCHF, but some people may have issues like yours when starting out, in the first days or weeks.

One way to control it would be to use over-the-counter antacids, like Omeprazole, during the limited period of time that you are likely to experience this symptom.

Andreas Eenfeldt


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  1. Johan
    Too bad the second answer doesn't really answer the question, as this is something I have been wondering too. Yes, it's hard to overeat on a low carb diet, but what happens if you do overeat anyway? What happens with excess fat that we take in, if it is not stored as fat in the body? How does the body use the rest of the energy from the extra fat?
    Reply: #4
  2. EvgeniaBB
    I think that if you do overeat the too many fat calories have 4 ways to go:
    1) a part won't be absorbed, because your ability to digest fat is not unlimited
    2) a small part will be stored as fat
    3) your metabolism will increase, which is not a very pleasant thing, particularly at night. You'll be hot and willing to move
    4) it will be compensated the next time you eat as fat digestion is very slow and takes longer than a whole day. You'll just feel less hungry later and probably will eat less next time

    But it's only my guess

  3. Michaela
    Acid reflux: I do have this after drinking some sorts of tea or sparkling water (carbonated water).
    I then want ro chew some almonds or take some small swallows of sugarless almond drink without carbs (Provamel, Alpro ...). The acid vanishes immediately (and without drugs).
  4. carol
    According to Chris Masterjohn, ketosis is shut down by excess energy intake. Overeating is less likely to happen on lchf, but if you are like me, it does sometimes happen. You need to be more aware of your portions and limit your eating. IF helps.
  5. Joy
    Make sure you are drinking 8 glasses of water a day,document this daily. For indigestion my hubby takes 1/2 teaspoon of baking soda in a small glass of water. It usually works in about 30 min. For him. Can't say if it is safe to do this, however I have known a few people that says it helps.
  6. Kit Kat Girl
    Ive not been as diligent as I hoped but I mostly stay on the low-carb eating lifestyle. I noticed that Im losing more inches than weight, though Ive lost more than 20 lbs, yay! Ive noticed that Ive gone from 2x clothes to wearing some clothes in size 14! Is this normal to lose more inches than weight?
  7. LowCarb Finn
    Acid reflux on keto:
    It might also be the body protesting foods it does not like. Examples of LCHF foodstuffs I just cannot eat:

    * I would love to eat pork. especially feet, skin etc, but my body signals its displeasure by mild TWO DAY heartburn from a single meal of pork.
    * From low lactose and non lactose dairy products I get 12 hour nausea without being able to vomit. (No surprise, the removal of lactose is a heavy industrial process.)
    *From coconut in any form whatsoever - both cold pressed organic oil and industrial coconut fat, coconut flakes, coconut sugar, whatever - I get a feverish feeling for a day or so plus sore throat.
    *From tomato in any form I get watery diarrhea inside an hour or two; I suspect the body wants to get rid of it as soon as possible and that's the way to do it..-

    And I am NOT allergic to any of these foods. Everyone is just not supposed to be able to eat everything possible.

    So if anyone gets acid reflux or any other weird symptom from goin keto or LCHF, the question then is: Are you eating something you usually don't, when you go keto/LCHF?

  8. Russell
    Acid Reflux remedy - I am not a doctor or anything but I have recently read that most acid reflux can be fixed by adding HCl with Pepsin, Apple Cider Vinegar and digestive enzymes supplements before each meal.... the real cause is low stomach acid because we lose stomach acid as we age.... losing stomach acid causes digestion problems and a myriad of symptoms.... replenishing stomach acid is one of the most important things you can do to help your body out....
  9. Valerie
    Reflux--if you've increased your intake of coffee or tea (e.g., the introduction of bulletproof coffee for breakfast), that could be the source. Personally, I can handle pretty much unlimited amounts of green tea, but black tea leads to quite a bit of pain.
  10. Obehi
    I have been on the keto diet for over 3 weeks , I started going back to the gym today and tried lifting weight and doing cardio and it exhausted me . This is very disturbing because the gym is my life.
    Reply: #12
  11. 1 comment removed
  12. Kristin Parker Team Diet Doctor

    I have been on the keto diet for over 3 weeks , I started going back to the gym today and tried lifting weight and doing cardio and it exhausted me . This is very disturbing because the gym is my life.

    It can take about 4-6 weeks to become fat adapted. When that transition happens, your body will be burning fat for fuel instead of glucose.

  13. John Q Public
    Sounds like a whe lot of folks have a whole lot of uvly side effect from keto.
    Reply: #14
  14. Charlotte Zwart Team Diet Doctor

    Sounds like a whe lot of folks have a whole lot of uvly side effect from keto.

    This differs from individual to individual. Read our guide on side-effects and what to do about them here: https://www.dietdoctor.com/low-carb/side-effects

  15. Debra Brooks
    Youre mostly going to hear of the problems with this low carbs on this site. That is why it is here. Everyone has different side effects from different food intake. You have to listen to your body and try to do whats best for YOU. When I wasn't on low carbs, I had horrible side effects from my regular diet. I was obese, joint aches, heartburn, borderline diabetes, borderline hypertension, GERD etc. etc. etc. Now, since being on low carbs for the most part of the last 20 years, all of the above issues are gone. So, in my opinion, the side effects mentioned on this site are minimal to the benefits and are treatable and changeable with patience. Good luck to all of us.

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