How much fat should you eat on low carb or keto?

Are you hungry? Don’t be. When you start a low-carb diet and cut back on carbohydrates, the trick is to fuel your energy needs with fat instead.1

How much fat should you eat? It’s not a very exciting answer, but the real answer is, “It depends.”

Although we have essential fatty acids that we need to eat, we do not have a pre-defined amount of fat we should eat like we do with protein.2 That is why our three rules of low-carb eating are:

  1. Reduce carbohydrate to the desired level
  2. Get adequate protein at nearly every meal
  3. Use fat as needed for fullness and flavor

Fat supplies those extra calories and extra energy that we used to get from carbs. You should eat enough fat to stave off hunger between your meals. Shoot for feeling pleasantly satisfied, but not overfed after each meal. After dinner, you should make it easily through the night – 12 hours without hunger (if not more). Work towards finding this balance.

Below are a few refinements to this advice, if you really want to maximize the effectiveness of your low-carb diet.

Key takeaways

1. Don’t fear fat

For decades we have heard the message that we should reduce the amount of fat.3 We now have plenty of evidence showing this is incorrect and misguided advice, especially when it comes to low-carb diets.4 However, the lingering fear of fat may remain for many people. Step one to getting the right amount of fat for you is to move past any fear that eating fat makes us fat, or that eating fat is automatically bad for our health.

You can learn more in our guides on healthy fats, saturated fat, and 10 ways to eat more fat.

2. Ease into fat adaption

When you begin your low-carb journey, you may find some high-fat foods taste ‘too rich.’ Be patient. As you transition to your new way of eating, both your body and your taste buds will adjust.5 Work up to eating enough fat to avoid hunger and allow your body time (at least a month) to settle into its new pattern of burning fat instead of carbohydrates.

When you find that balance, hunger will likely diminish as your body enjoys easy access to the body’s fat stores that were locked away by a high-carb diet.

3. Dial back for weight loss

Hoping to lose weight? If the answer is yes, once you are at ease with your low-carb diet, experiment with reducing the extra fat you add to meals.

Eat just enough to avoid hunger – let your body burn its internal fat stores rather than that extra pat of butter. This will likely accelerate weight loss. 6

But don’t go too far – when hungry, always opt for additional protein or fat rather than deviating from your low-carb plan.

4. Add fat as needed for maintenance

Once you reach your goal weight, you may no longer have the internal fat stores necessary to fuel an energy shortfall day after day. Tune into your body’s hunger signals. Now is the time to gradually add more fat to your diet until you find the satisfying balance of hunger-free weight maintenance.

5. Eat an adequate amount of protein

Part of the trick of minimizing hunger is making sure you eat the right amount of protein. For most people, this happens naturally. But, if you can’t beat your hunger by adding fat, or if you are eating very low-carb but stalled in weight loss, take a look at how much protein you are eating.

How much is enough? Individual needs vary, but about 1.2-1.7 gram of protein per kilogram of reference bodyweight (each day) may be optimal for weight loss. You may need more if you are active though, especially if lifting weights and building muscle.

Learn more about protein on a low-carb or keto diet

6. Optional extra details

If you’re interested in even more details and discussion about adapting the amount of fat and protein to your exact needs, and your situation, watch the interview below with Dr. Ted Naiman. Most people don’t need that much fine-tuning, but it’s a helpful video if you are looking for extra-credit.

Is Obesity Caused by Too Much Insulin? – Dr. Ted Naiman


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  1. Just because you can eat more fat for fuel, doesn’t automatically mean that you will. In studies when people are eating low-carb, moderate protein idets and are allowed to eat as much fat as needed to feel full, they often end up consuming less overall due to feeling fuller and more satisfied:

    Nutrition & Diabetes 2017: Twelve-month outcomes of a randomized trial of a moderate-carbohydrate versus very low-carbohydrate diet in overweight adults with type 2 diabetes mellitus or prediabetes [randomized trial; moderate evidence]

    Annals of Internal Medicine 2005: Effect of a low-carbohydrate diet on appetite, blood glucose levels, and insulin resistance in obese patients with type 2 diabetes [non-randomized trial; weak evidence]

    Nutrition & Metabolism 2005: A low-carbohydrate, ketogenic diet to treat type 2 diabetes [non-randomized trial; weak evidence]

  2. Journal of Food Science and Technology 2014: Essential fatty acids as functional components of foods- a review [overview article; ungraded]

  3. Circulation: 2013 AHA/ACC guideline on lifestyle management to reduce cardiovascular risk: A report of the American College of Cardiology/American Heart Association task force on practice guidelines [consensus guidelines; ungraded]

  4. Saturated fat has long been the main dietary fat of concern. But evidence shows that quality science does not support the dangers of saturated fat. A 2010 review of cohort studies found “…no significant evidence for concluding that dietary saturated fat is associated with an increased risk of CHD or CVD”:

    The American Journal of Clinical Nutrition 2010: Meta-analysis of prospective cohort studies evaluating the association of saturated fat with cardiovascular disease [moderate evidence]

    Meta-analyses of observational studies in 2015 and 2017 reached the same conclusions about the lack of association between saturated fat and heart disease:

    British Medical Journal 2015: Intake of saturated and trans unsaturated fatty acids and risk of all cause mortality, cardiovascular disease, and type 2 diabetes: systematic review and meta-analysis of observational studies [moderate evidence]

    British Journal of Sports Medicine 2017: Evidence from prospective cohort studies does not support current dietary fat guidelines: a systematic review and meta-analysis [moderate evidence]

    And low carb, high fat diets have been used to treat and even reverse type 2 diabetes and reduce overall cardiovascular risk

    Diabetes Therapy 2018: Effectiveness and safety of a novel care model for the management of type 2 diabetes at 1 year: an open-label, non-randomized, controlled study [weak evidence]

    Frontiers in Endocrinology 2019: Long-term effects of a novel continuous remote care intervention including nutritional ketosis for the management of type 2 diabetes: A 2-year non-randomized clinical trial [weak evidence]

  5. This is based on consistent clinical experience of low-carb practitioners. [weak evidence]

  6. This is based on consistent clinical experience of low-carb practitioners. [weak evidence]