Do you need a low carb diet to lose fat? Just like most answers in this world: it depends… The amount of carbs that a specific person should be eating to lose fat is based primarily on their sensitivity to insulin.
The quick summary is that those that have relatively high sensitivity to insulin will be able to eat more carbs and have generally the same fat loss results as eating less carbs. However, those with relatively low sensitivity to insulin will benefit much more with regards to fat loss by sticking to a lower-carb diet rather than a higher-carb diet.
In the end, every person is different, so the only way to find the optimal level of carbs in your diet is to experiment. First, start with a reasonable level of carbs in your diet around the 40-50% range, and then continue reducing this percentage of carbs in your diet and measuring the results. If by cutting from 40% to 30%, you see significant fat loss, then either maintain this percentage or continue to cut until you reach your fat loss goals.
However, if you are substantially cutting your carb levels in your diet and not seeing much in the way of fat loss, this could mean that you have high sensitivity to insulin and that cutting more carbs won’t result in anymore meaningful fat loss. So given the choice of eating more carbs or less carbs with the same results, I’m guessing most people are going to go with more carbs!
- Cutting carbs is still a popular plan for fat loss, but for lifters, higher carb diets actually produce the same results.
- If you’re an active lifter and training hard, try starting your fat loss diet as high as 50% carbohydrates and then adjusting down only if it’s needed to continue seeing progress.
- Going by how you think you “feel” is misleading. It’s more important to chart progress and make adjustments based on the results you’re actually getting.
Low Carb Isn’t Always The Answer
Let’s say two people need to drop fat and improve their body composition. One guy is an out of shape 40-something stockbroker and the other is an in-shape movie star getting ready for his latest action movie.
What should they do, diet-wise?
Most people, and many coaches, would tell them both to cut down their carb intake. But it’s ridiculous to give these two individuals the same nutrition plan, just like you wouldn’t give them the same training plan.
For the longest time, the go-to answer for fat loss dieting has been “eat less carbs,” and at its most basic level, eating less carbs is good advice and most people would benefit from eating fewer carbohydrates.
But what we’re discovering is that the level of carbohydrates that you can consume while still losing weight is directly related to your insulin sensitivity.
Drastic carbohydrate restriction is unnecessary, maybe even counterproductive, for people with good insulin sensitivity because it doesn’t improve fat loss. So giving our stockbroker and movie star similar diets wouldn’t make sense.
Besides, if you could eat as many carbs as possible and still reach your body comp goals, wouldn’t you?
Insulin Sensitivity: Research and The Real World
Two particular studies have explored carbohydrate cut-off points for producing maximum fat loss while paying attention to individual insulin sensitivity.
In the first study, researchers wanted to look at long-term differences in body composition between a low fat diet and a low glycemic load diet.
They found that after 18 months, regardless of the diet plan participants were put on, they all experienced similar changes in body composition. Chalk that up as a win for the “a calorie is a calorie” crowd, right?
Well, not so fast.
In a secondary analysis of the data, the researchers separated study participants by insulin sensitivity. They found that the people with the worst insulin sensitivity had the best body composition changes on the low glycemic diet.
It didn’t matter what diet the people with the best insulin sensitivity were put on. They got just as lean either way.
In another study, known as “the A to Z Study,” researchers put people on one of four popular diets: Atkins, Zone, Ornish, or a control diet (“traditional” low fat).
At the end of 12 months, people on the Atkins diet lost the most weight. So, that’s proof that low carb diets rule, right? Again, not exactly.
In a secondary analysis of this data, researchers compared the highest carb diet (Ornish) and lowest carb diet (Atkins) and related weight loss to study participants’ insulin sensitivity.
Just as in the previous study, people with the poorest insulin sensitivity lost more weight on the lower carb approach. People with the best insulin sensitivity lost the same amount of weight regardless of diet.
I’m a believer in the benefits of carbohydrate restriction, but I’m also a big believer in the fact that carbs are delicious.
If cutting your carbs from 40% down to 20% of calories won’t give you any additional fat loss benefit, then why do it? It makes more sense to lose as much fat as you can with your carbs at 40% of total calories and then reduce them after your fat loss begins to slow.
These two studies showed that an individual’s insulin sensitivity clearly influences the level of carbohydrates necessary to maximize fat loss. But neither study looked at the role of exercise as part of the fat loss strategy.
Exercise, especially weight training, can increase muscular insulin sensitivity. This increases the amount of carbohydrates you can consume and shunt towards your muscles automatically.
It’s also important to note that the carbs you cram into your muscles right before, during, and right after training tend to stay there as your muscles don’t have the enzymatic machinery necessary to release sugar from glycogen to the rest of your body.
As a lifter, your insulin sensitivity should be better than most, so you’ll likely find yourself in a place where you can lose just as much fat with a relatively-higher carbohydrate intake.
However, this approach isn’t a free pass to gorge on carbs and simply hope for better abs. You can’t eat carbohydrates recklessly and then get upset when your body composition isn’t improving.
Starting your body composition training with a higher overall carb count will give you greater flexibility to reduce carbs further into your dieting phase when calories are at a premium, and tracking your progress along the way is crucial to deciding when and if to make changes.
Making Higher Carbs Work For You
Don’t start any body comp diet phase with your carbohydrates any lower than 40% of your total calories, then adjust from there based on weekly, biweekly, or even monthly progress.
While the A to Z Study did include the Ornish diet, which has upwards of 65% daily calories from carbs, 50% of calories from carbs is generally the maximum you want to work with because it’s important to remember that everything in your diet is connected.
As you eat more carbs, you’ll need to eat less of something else, remembering that total calories are capped at a specific level since you’re in a fat loss phase.
You want to keep your protein intake around 30% of your total calories and never lower than 1.6g/kg bodyweight.
The rest of your calories will come from fat, which in this case is the remaining 20% of calories. So at the high end of your carb intake, your diet could look like this:
But if you’re looking to lose as much fat as possible while eating as many carbohydrates as possible and you have good insulin sensitivity, this is how you should start.
Be a Science Experiment
Don’t blow this idea off because it doesn’t “feel” right to eat a 50% carb diet or because carbs make you “feel” fat. Optimizing body composition is much less about how you feel and more about how your body changes.
It drives me crazy when people say they “feel leaner” a few weeks into a new diet. You eitherare leaner or you aren’t. It doesn’t matter how you “feel.”
Treat your body like a science experiment. Put the plan into action, and then track and measure how your body responds.
If you commit to making adjustments based on how your body has actually responded, not how you “feel” about your body’s response, your newly visible abs will thank you.
Get the full article and images at t-nation.com