Why “Low-Calorie” Foods Stop Weight Loss

Why “Low-Calorie” Foods Stop Weight Loss

While the world—thanks to documentaries like Fed Up—is getting wise to the sugar-induced health epidemics that are plaguing the U.S. in particular, many of us are still addicted to sweetness, in all of its guises. And what’s more, hold the belief that low-calorie, sugar-free, and fat-free foods are a potential antidote to gaining weight.

But according to Dr. Laura Lefkowitz, an M.D. who specializes in nutrition and health counseling, they are trojan horses—not only for what they do to our blood sugar levels and taste buds, but also because label math never checks out. Because we’ve received many questions about synthetic diet foods in our inbox, we put a few of them to her. (She also wrote our pieces on Why Most Diets Fail, and Hormones, Weight Gain, and Infertility.) Have other questions? Drop us a line at [email protected] or tweet us @goop.

A Q&A with Dr. Laura Lefkowitz


Is there a difference between real versus synthetic foods when it comes to weight loss? I.e., are whole grains better than refined, are sugars from fruit better than synthetic sweeteners?


If your goal is to eat “healthy,” not specifically to lose weight, then there is a huge difference in natural versus synthetic, processed foods. Whole grains, fruit, and natural sugars (agave nectar, honey, etc.) contain more nutrition (vitamins, minerals, phytonutrients, fiber, etc.) than refined grains, flours, and sugars. But when it comes to actually losing weight, the difference is minimal.

When I tell my patients that even fruit can block their weight loss, it is as though I am shattering their entire belief system.

Hormonally-Blessed patients have systems that work efficiently and they can tolerate a fair amount of whole grains and natural sugar in their diets and still lose weight. In their case I do recommend eating whole grains, whole pieces of fruit, and natural sweeteners in lieu of refined or synthetic, because they will be getting nutrients with their calories that will help them maintain a healthy body. Synthetic, refined sugars have no accompanying nutrition and therefore aren’t bringing any benefit—just calories, inflammation, and weight gain. But even the Hormonally-Blessed must reduce the amount of whole grains and natural sugars in their diets if they want to get ultra lean.

On the opposite side of the spectrum, if you are Hormonally-Challenged (chronic dieters and people who have a hard time losing weight), it makes very little difference how “whole” or “natural” your source of carbohydrate or sugar is, it will all block your ability to lose weight.

Whole wheat flour, white flour, quinoa flour, protein powder, etc. all look exactly the same; a fine powdery particle that look just like white sugar. I’ve never seen anyone lose weight because they switched from a white bagel to a whole wheat bagel, or white to brown rice.

If you want to lose weight, there is no difference between sweetening your coffee or tea with honey, agave nectar, brown sugar, or white sugar. It doesn’t matter how healthy something looks or sounds. Once it reaches your intestines it’s all absorbed into your bloodstream as sugar, which causes the release of insulin, a fat storage hormone, which can block your ability to shed pounds.


Why is that?


Weight loss is not as simple as how many or few calories or grams of sugar, or what type of sugar (natural or synthetic) are ingested. There are many factors that contribute to how food is perceived by your body and how much fat storing insulin will be released every time you eat. The following points are essential to keep in mind when consuming any type of sugar:

1. Caloric Load. How many calories you are eating at one time or portion control. There is a big difference between eating 1/2 a cup versus 3 cups of fruit salad, or 1 cup of ice cream versus a whole pint at one sitting. The larger the sugar load at a point in time, the more fat storing insulin you will need to release to control your blood sugars.

2. Rapidity at which blood sugar levels rise. Blood sugars rise very rapidly from a smoothie or a juice and your body will have to pump out a lot of insulin quickly to get the sugar out of your bloodstream. If you eat whole pieces of fruit it will take longer to break down and absorb the sugar from fruit, leading to a slower blood sugar rise, and less insulin release.

3. Thermogenics. This describes how hard your body has to work to breakdown the food you consume before it enters your bloodstream. Your body actually burns calories digesting food. Foods like whole fruits and vegetables with difficult to digest cellular material (roughage) and very little inherent caloric content make the body work very hard to break them down for absorption into the bloodstream. Processed or foods altered from their original state like a smoothie or juice, bypass this thermogenic process as liquid requires no digestion. There is a big difference between eating a fresh vegetable salad and eating vegetable soup puree, or between eating fresh tomato chunks and drinking V-8.

4. Sugar pairings. The foods you consume your sugar with, i.e. fat, fiber, and protein, slow down the digestion and absorption of sugar, causing a slower rise in blood sugars and less insulin release. If you eat fruit on an empty stomach your blood sugar will rise more rapidly than it would if you ate fruit on a salad (fiber), with yogurt (protein), or peanut butter (fat).

5. Timing of sugar consumption. Your body’s ability to process carbohydrates (called insulin sensitivity) decreases as the day goes on. That means you’ll more efficiently metabolize carbohydrates in the morning compared to later at night in bed. The more efficiently your body can use the food you eat, the easier it is to lose weight.


What do you think about low- or reduced-calorie foods? Is zero calorie always zero calorie?


Zero calorie and low-calorie foods are not all they’re cracked up to be. From age 17-28 I lived on diet coke, zero calorie salad dressings, and low calorie foods like frozen yogurt, and I watched the numbers on the scale rise.

You can buy sugar-free candy and low-fat or fat-free everything these days, so why is our nation getting heavier? Food labels are not telling the whole picture.

One of the first things I learned when I started practicing nutrition was, “DO NOT BELIEVE FOOD LABELS!!!” Food labels are manipulated to read how you want them to read, so you will buy the product. They manipulate portion sizes to have the caloric content that is appealing to consumers, i.e. the 100 calorie pack. Most people eat 2-3 times the portion or serving size that is on the label and don’t even realize it!

There are regulations for food labels. If a serving size has less than a certain amount of ingredient, i.e. partially hydrogenated oil, they don’t have to include it on the label. When you look at the label of sugar-free, fat-free creamer, it reads:

Serving Size: 1 TBSP (who actually uses just 1 TBSP?)
Calories: 15
Total Fat: 0
Cholesterol: 0
Sodium: 10mg
Total Carb: 3g
Fiber: 0g
Sugar: 0g
Protein: 0g

Salt doesn’t have any calories, it’s a mineral. So where are you getting 15 calories per tablespoons from? The 3 grams of total carbs. Where are those carbs from? Is 2 tablespoons 30 calories? No!

If you look at the ingredients it says:
1. Water
2. Corn Syrup (SUGAR, they say adds a trivial amount, but not if you use more than one serving, it adds up)
3. Palm Oil (FAT!!! But it says fat-free!)
4. Sodium Caseinate
5. Natural and artificial flavors, etc. (i.e., more and more chemicals and artificial sweeteners)

If you use more than 1 tablespoon of this creamer you are getting a significant amount of sugar (corn syrup) and fat (palm oil) in your coffee, without even realizing it. Furthermore, 2 tablespoons of fat-free, sugar-free creamer is more than 30 calories. But the label leads you to believe it is insignificant and you can pour it in. A few tablespoons might not matter, but day after day, week after week, month after month, those extra servings of corn syrup and palm oil add up and become significant—they can lead to weight gain or block weight loss.

Traditional mathematics does not apply to food labels. A nutrition label describes the nutritional breakdown for just that specific serving size.You cannot extrapolate food labels. Quite simply: 1 plus 1 does not equal 2 in nutrition labeling.

In medical school I was overweight and tried a popular calorie counting weight loss program. At that time it assigned Points to foods based on calorie content.

In this program a ½ cup of blueberries was 1 point. But 1 cup of blueberries was 2.5 points. I found this very confusing. Doesn’t ½ cup blueberries + ½ cup blueberries = 1 cup of blueberries? Shouldn’t 1 point + 1 point = 2 points? Why 2.5 points? Where did that extra ½ point come from? Because food labels don’t add up. 1 cup of blueberries is more calories than the specific measurement for ½ cup of blueberries. Add these half points up throughout the day and they will make a big difference if you are using a “calorie counting” method for weight loss, where you have to consume less than you burn. This is why many people who calorie count do not see any weight loss: The calculations simply don’t add up. They are ingesting more calories than the labels lead them to believe.


Are there hidden calories in diet soda?


Diet soda is an interesting topic.

Diet soda is made of water, artificial sweeteners (which have insignificant calories), carbonation, coloring, and flavoring. They contain zero or minimal calories, even if you drink multiple diet sodas, but I discourage using them for a different reason.

The first problem with artificial sweeteners is that they affect the body’s ability to gauge how many calories are being consumed. Some studies show that sugar and artificial sweeteners affect the brain in different ways.

The human brain responds to sweetness with signals to eat more. By providing a sweet taste without any calories, artificial sweeteners cause us to crave more sweet foods and drinks, which can add up to excess calories consumed. So you drink Diet Coke to avoid cookies, but then have intense cravings, cave in, and end up eating sweets anyway.

The second problem with artificial sweeteners is how they affect our senses. When the taste buds on your tongue taste something sweet like Coke Zero, they send a single to the brain that says, “Sugar is coming!” The brain then sends a signal to the digestive tract saying, “Heads up down there, something sweet is coming. Tell the pancreas to pump out some insulin to control the situation.”

I’ll explain why this is problematic with an example:

It’s 11am and you’re getting hungry for lunch, but you don’t want to eat yet, so you say to yourself, “I’ll have a Diet Coke or a coffee with Stevia to tide me over until 12pm, then I’ll eat lunch.” Sounds like a reasonable plan. If you are hungry at 11am, it means your blood sugars are probably already pretty low. Now you drink artificial sweeteners with no calories and trick your body into releasing insulin, but there is very little sugar in your blood for the insulin to shuttle to your organs, so whatever little sugar was left in your bloodstream at 11am is now shuttled out, your blood sugar drops lower and you become “hypoglycemic” or “low blood sugar.” Now your body is in panic mode because it cannot function with low blood sugars and sends out intense signals and hormones for you to eat to raise your blood sugars back to normal range.

It is very hard to control your food intake when you are hypoglycemic because you need sugar right away to feel normal. If you are hypoglycemic and eat a salad with chicken breast, it will take at least 30 minutes to start digesting that salad and raise your blood sugar levels. The body can’t wait that long, it’s too dangerous. The body makes you crave easily digested foods or beverages that will return blood sugar levels back to normal range as quickly as possible.

Fast forward to noon when you finally eat your lunch. Your blood sugars are so low you can’t resist eating the bread or croutons that comes with your salad, or crave fruit or sweets right after you have eaten lunch, to bring your blood sugar levels back up. Now you are back to raising your insulin levels again and perpetuating this cycle of high and low blood sugars. By 3pm you are dying for coffee or sweets to pick you back up so you can make it through the rest of the day.

So while diet soda and diet foods like sugar-free gum have insignificant calories, the artificial sweeteners cause a viscous cycle of releasing fat storage hormones and causing low blood sugars that cause sugar cravings and regretful eating behaviors. Controlling your physiology is the key to controlling your weight and behaviors around food. It is hard to have willpower when your body is physically in need of sugar.

The third problem with artificial sweeteners is a phenomenon I call “escalation.” Artificial sweeteners are far sweeter than regular sugar. Equal is 180 times sweeter than sugar. Splenda is 600 times sweeter than sugar. The natural health industry’s golden child, Stevia, is 300 times sweeter than real sugar. Why is this important? Artificial sweeteners disrupt the way our brains register natural sugar. These intensely sweet substitutes alter our reaction to sugar and make us think that real sugar is not sweet enough. Hence you need more and more real sugar to excite your brain and feel satisfied.

I was a living example of this phenomenon of “escalation.” When I was in medical school and doing my residency, I was 30lbs heavier than I am today. First thing on the way to the hospital I grabbed a Diet Coke. When I got to the hospital I would drink two coffees with two Splendas. I drank more Diet Cokes throughout the day to keep myself from eating sweets that were all around the hospital. I was constantly dieting, and for breakfast I would have a plain 0% greek yogurt with a banana and a packet of Equal. At first I used one packet of Equal, but soon I needed two for my yogurt to taste sweet. Eventually I was adding 3-4 packets of Equal to my breakfast. If I ate a piece of ripe fruit is didn’t taste sweet to me, I needed to add a spoonful of sugar or sweetener to excite my neurons and feel satisfied.

Why did I have to keep escalating the dose of artificial sweeteners to achieve the same level of taste and neurotransmitter excitation? The brain desensitizes and adapts itself over time. My brain realized that the artificial sweeteners were not real sugar with calories, so it was dulling my senses to them—I needed more and more to overcompensate and achieve the same level of satisfaction. It’s the same mechanism for why a drug addict needs more and more drugs over time to achieve the same high.

Once I understood this phenomenon, I went cold turkey and eliminated all artificial sweeteners from my life. I’ll admit I was miserable for about two weeks, but then my brain started adapting. Fruit and vegetables started having taste and flavor again. My blood sugars stabilized, and I was able to lose 30lbs through clean eating.

Artificial sweeteners have many other negatives and side effects, and the less you use them, the better of you will feel. Don’t believe food labels. They are exploiting your vulnerabilities. Read the ingredients and decide if what they are claiming makes sense on a practical level. If the majority of the food you eat are not packaged without food labels you will be drastically better off.

Dr. Laura J. Lefkowitz graduated from SUNY-Stony Brook School Of Medicine in 2002, where she received her M.D. with honors in Obstetrics and Gynecology, Psychiatry, Internal Medicine, and Radiology. Dr. Lefkowitz’s interests then shifted from treating disease in the traditional sense and she refocused her attention on prevention and treatment through nutrition and self-care. She attended Columbia University’s Institute for Integrative Nutrition where she has studied many different dietary theories and complementary treatments to traditional medicine. Dr. Lefkowitz works in Florida, and consults patients via Skype.