What to do about a lack of energy on low carb?


Is a low-carb diet appropriate for someone who has had gastric-bypass surgery? Can you lose weight on low carb while taking insulin? And what to do about a lack of energy on low carb?

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

Low carb and gastric-bypass surgery?

Is a low-carb diet suitable for someone who has had a gastric bypass surgery?


Yes, very much so. As it’s hard to eat more than small amounts after surgery, it’s a great idea to avoid nutrient-poor carbohydrates (like bread). It’s also a great way to stop and reverse the regain of weight that often happens a year or so after surgery-induced weight loss.

Here’ are several happy people who have tried it:

Andreas Eenfeldt

Question about insulin

Can you lose weight on this type of diet while taking insulin?


Yes. However be aware you’ll need LESS insulin on a low-carb diet. Be very careful when starting out so that you don’t overdose your insulin, resulting in hypoglycaemia.

Reducing insulin doses by adapting them to your lower needs on low carb will also help with weight loss.

Starting low carb with diabetes medications, e.g. insulin

Andreas Eenfeldt


Lack of energy

Hello Dr. Andreas,

I have been following the keto diet since January and I am very pleased with the diet overall. I have lost 20 lbs (9 kg) and it’s been fairly easy to follow the plan. I have had some problem with leg cramps, but the biggest issue I have had is a lack of stamina when I am active. I love to go on hikes and bike rides and since on this diet I don’t feel I have the same endurance I had in the past. Any thing I can do, or eat that may help before I take a hike?


Yes, get some extra salt and fluid. Like a cup or two of bouillon, or a few grams of salt diluted in water. This may help to increase energy generally on low carb, if so the effect should be noticed within 15-30 minutes.

If that does not help enough, you may benefit from a moderate amount of carbs before those physical activities, like a small amount of rice or a few potatoes with a meal.

Learn more about how to increase physical performance on low carb

Andreas Eenfeldt


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