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 eat enough protein and fibrous veggies, and then fuel your remaining energy needs with fat.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 don’t 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:
- Reduce carbohydrate to the desired level
- Get adequate protein at nearly every meal
- Use fat as needed for flavor and, if needed, extra calories
Fat — either from our food or from our fat stores – supplies those extra calories and extra energy that we used to get from carbs. You should eat enough fat to enjoy your meals and to stave off hunger between your meals if needed. 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.
- Don’t fear fat
- Ease into fat adaption
- Dial back for weight loss
- Add fat as needed for maintenance
- Eat an adequate amount of protein
- Optional extra details
1. Don’t fear fat
For decades we have heard the message that we should reduce the amount of fat in our diets.3 In terms of scientific evidence, links between saturated fat and heart disease are weak and inconsistent.
Although some reviews of the literature do find a weak relationship, an increasing number of meta-analyses and systematic reviews find that there is no significant connection between saturated fat and heart disease.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.
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.
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 enjoy your food – let your body burn its internal fat stores rather than that extra pat of butter. This will likely accelerate weight loss.6
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 adjust the fat in your diet until you find the satisfying balance of hunger-free weight maintenance.
5. Eat an adequate amount of protein
The most helpful trick to minimizing hunger is making sure you eat the right amount of protein. If you are eating very low-carb but have stalled with weight loss, or if you find yourself hungry between meals, take a look at how much protein you are eating.
How much is enough? Individual needs vary, but about 1.2-2.0 grams of protein per kilogram of reference bodyweight (each day) may be optimal for weight loss.7 You may need more if you are active, especially if lifting weights and trying to build muscle.8
Healthy fats on a keto or low-carb diet
Guide Fat is one of the three macronutrients (“macros”) found in food. On a keto or low-carb diet, fat is your primary energy source, so choosing healthy types and eating the right amount is important. Here’s a guide to everything you need to know about fat on a carb-restricted diet.
The top 10 ways to eat more fat
Guide Don’t fear fat. Fat is your friend. Flavorful, full-fat ingredients topped with creamy, satisfying sauces… Low-carb and keto eating can be decadent! Fat is an amazing flavor enhancer, it makes everything taste better. Here are the top 10 tips on how to eat more fat – plus tips on HOW much fat you should aim for.
Just because you can eat more fat for fuel, doesn’t automatically mean that you will. In studies where people are eating low-carb, moderate-protein diets 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 [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]
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] ↩
Here are four meta-analyses showing no connection between saturated fats and heart disease:
- Open Heart 2016: Evidence from randomised controlled trials does not support current dietary fat guidelines: a systematic review and meta-analysis [strong evidence]
- Nutrition Journal 2017: The effect of replacing saturated fat with mostly n-6 polyunsaturated fat on coronary heart disease: a meta-analysis of randomised controlled trials [strong evidence]
- Annals of Internal Medicine 2014: Association of dietary, circulating, and supplement fatty acids with coronary risk: a systematic review and meta-analysis [meta-analysis of observational studies and RCTs; moderate evidence]
- PLOS ONE 2016: Is butter back? A systematic review and meta-analysis of butter consumption and risk of cardiovascular disease, diabetes, and total mortality [meta-analysis of observational studies; very weak evidence]
When looking at RCTs, this review found no relationship between saturated fat and heart disease, though it did find a relationship when looking at observational studies.
A 2020 Cochrane review of RCTs showed a modest reduction in cardiovascular events for lower saturated fat intake. But it found no benefit to lowering saturated fat intake for heart attack, stroke, cardiovascular death, or all-cause death.
British Journal of Nutrition 2020: The effect of 12 weeks of euenergetic high-protein diet in regulating appetite and body composition of women with normal-weight obesity: A randomised controlled trial [randomized trial; moderate evidence]
The Journal of Nutrition 2013: Normal protein intake is required for body weight loss and weight maintenance, and elevated protein intake for additional preservation of resting energy expenditure and fat free mass [randomized trial; moderate evidence] ↩
Nutrients 2018: Effects of a high-protein diet including whole eggs on muscle composition and indices of cardiometabolic health and systemic inflammation in older adults with overweight or obesity: a randomized controlled trial [moderate evidence]
The American Journal of Clinical Nutrition 2017: The effects of dietary protein intake on appendicular lean mass and muscle function in elderly men: a 10-wk randomized controlled trial [moderate evidence] ↩