Tag Archives: keto diet

Which Diet Works Best For Weight Loss?

In the ongoing nutritional war between adherents of low-fat and low-carb diets, the skeptical cardiologist has generally weighed in on the side of lower carbs for weight loss and cardiovascular health.

I’ve questioned the vilification of saturated fat and emphasized the dangers of added sugar  and I consider myself a keto-friendly cardiologist.

Recently I stumbled across a good review on the scientific evidence of various popular diets for weight loss. Obesity and its health consequences are clearly increasing and impacting the cardiovascular health of millions. As such, as a cardiologist it would be great to have a one true diet that is best for weight loss for my patients.

Unfortunately, as I discussed in my analysis of the DIETFITS study there isn’t a one size fits all dietary silver bullet. This recent review does a good job of analyzing the data and has some nice graphics.

Here’s the first graphic which summarizes the food groups allowed for 7 of the most popular diets

Is there any food group we can all agree on?

Yes, the non-starchy vegetables!

Dr. P’s Heart Nuts come in a close second (outlier Ornish recommends “moderation”. Extreme outlier Esselsytn who eschews all oils forbids nuts.)

Interestingly, the only one of these diets that bans red meat, chicken, seafood and eggs is the Ornish diet which is basically a vegetarian diet (see here for the lack of science behind this diet.)

Is there any food group that we all agree should be avoided? If we exclude the outlier Ornish  then there is unanimity that we should be avoiding added sugar and refined grains.

My recommended version of the Mediterranean diet says that high fat dairy is perfectly fine and actually preferred over processed skim or low fat dairy. Yogurt and cheese are encouraged.

Do Macronutrients Matter?

The second graphic nicely summarizes the macronutrient composition of these diets. The Atkins diet and ketogenic diets recommend less than 10% carbs whereas Ornish the outlier recommends less than 10% fat.

My recommended variation on the Mediterranean diet would lower the carb % to around 20% by avoiding starchy vegetables, most added sugar and most refined grains. I try to avoid ultra-processed foods completely. With this diet I am in some degree of ketosis (as measured by the fantastic Keyto device) most of the time although I’m not strictly following keto guidelines.

For example last night I had this delicious steak and smoked portabello quesadilla from Three Kings Pub. The tortilla alone contains about 40 grams of carbs, double the recommended amount for keto diets. I add elements of Three Kings Middle Eastern Sampler (Red pepper hummus, grilled eggplant relish, tzatziki, roasted head of garlic and dolmas. Served with grilled flatbread and an assortment of veggies) to get some of those universally acclaimed nonstarchy vegetables . I don’t utilize the balsamic reduction that is typically drizzled on the quesadilla because it tastes like pure sugar to me (sure enough it contains 11 grams of carbs)and I mostly avoid the grilled flatbread.

 Manipulation Of Diet Timing For Weight Loss

Breakfast is not the most important meal of the day and I only break my overnight fast when I get hungry which is typically around noon.

Variations on this type of intermittent fasting (periodic fasting or 5:2 diet, alternate-day fasting, time-restricted feeding, and religious fasting) have become popular. The review summarizes the science in this area as follows:

“There is growing evidence demonstrating the metabolic health benefits of IF. In rodents, these appear quite profound, whereas in humans they are sparse and need further investigation, especially in long-term studies. It has been suggested that IF does not produce superior weight loss in comparison with continuous calorie restriction plans [130], and there are limited data regarding other clinical outcomes such as diabetes, CVD, and cancer. IF diets seem safe and tolerable for adults…”

In other words, rats live longer with IF but we don’t know if humans do. If you find intermittent fasting helps you consume less calories through out the day and lose weight, go for it. For me fasting from 9 PM to late morning (typically 14-16 hours) give me greater energy and focus throughout the day and makes weight management simpler.

Conclusions: What Is The Best Diet For Weight Loss?

Both low carb and low fat fanatics will be disappointed in the conclusions of the review but I think it is reasonable:

There is no one most effective diet to promote weight loss. In the short term, high-protein, low-carbohydrate diets and intermittent fasting are suggested to promote greater weight loss and could be adopted as a jumpstart. However, owing to adverse effects, caution is required. In the long term, current evidence indicates that different diets promoted similar weight loss and adherence to diets will predict their success. Finally, it is fundamental to adopt a diet that creates a negative energy balance and focuses on good food quality to promote health.

I would

And here is the summary graphic

Dietetically Yours,

-ACP

N.B. With regard to the starchy vegetables, check out my “Potato Theory of Obesity.”

Source for images: Scientific evidence of diets for weight loss: Different macronutrient composition, intermittent fasting, and popular diets – ScienceDirect

And finally  (from  the  DietDoctor.com website) a graphic that illustrates the amount of healthy (nonstarchy!) vegetables that you would need to consume to reach 20 grams of carbs.

I Am A Keto-Friendly Cardiologist And I Love Keyto

The skeptical cardiologist has become more selective with regard to who he will accept as a new patient.  In practical terms this means I now call patients who want to see me and discuss with them why they want to see me, how they were referred or heard about me, and what their expectations are.

This might seem a little odd but turns out to be an excellent way for me to meet and smooth entrance for these newbies into my practice and gather important records and recordings prior to the first visit.

Recently, when I asked one of these potential patients why they had sought me as their cardiologist, the wife told me that through her internet research she had gleaned that I was a “Keto-friendly Cardiologist.”

Given that I have challenged conventional dogma on the dangers of dietary saturated fat and cholesterol and have written about ketosis (see here and here) a few times on this blog and defended Dr. Atkins I do actually consider myself “keto-friendly”.   However my prospective patient’s wife was not aware of the skeptical cardiologist as a blog writer.

How or why I was identified as Keto-friendly cardiologist was not clear.

I realized I needed to make it perfectly clear. It is now time to come out of the keto closet.

I am a “Keto-friendly cardiologist”!

I have dozens of patients who have been very successful using very low carb/high fat diets to help them lose weight and gain control of their diabetes and hypertension.

I don’t poo poo low carb high fat diets and I think they are vey compatible with a heart-healthy existence.

(I also advocate my version of a “plant-based diet“.)

In fact, lately I’ve gone back to dabbling with a Keto Diet myself.

To aid me in the dabbling I have found a device called Keyto to be the key to success and understanding of my ketosis.

Keyto: Breath Sensor for Ketosis and Weight Loss

When I went back to dabbling with ketosis in early 2019 I was using the Keto-Mojo finger prick device to measure my blood levels of beta hydroxybutyrate. I liked the precision this offered  compared to urine dip sticks but grew to dislike the need to prick my finger and create blood loss.

About a month ago I ordered I discovered the keto breath sensor KEYTO and have found since then that  it wonderfully simplifies  the process of being on a keto diet.

Keyto costs $99 and comes in a box the size of a video cassette  case.

In the box is the sensor device, four blowing mouthpieces, a very simple user manual, a AAA battery and a cute little bag for carrying the device

Ethan Weiss, MD, a highly respected preventative cardiologist and founder of Keyto includes a welcoming message for users which summarizes the mission of Keyto:

We designed the Keyto program to help you over-achieve your weight loss and health goals. With the Keyto Breath Sensor in this box, and the Keyto App on your phone, you have the key to unlocking success. You’ll be eating delicious foods, losing weight, and many  users even report an increase in energy and focus

Using Keyto Is Simple and Convenient

Getting started with Keyto is very easy: download the Keyto smartphone app, log in and follow the straightforward directions for pairing the breath sensor with the app.

Once paired via Bluetooth making measurements is easy. It’s important to understand the breathing technique needed and to facilitate this I strongly recommend watching the brief explanatory video Weiss has provided. Basically, you want to use a normal breath and blow for 10 seconds so that you are near the end of expiration when the device makes its recording.

To initiate a measurement you push the plus sign on the main “Journey” screen in the app then push the on button on the sensor.

Usually, if the sensor has been turned on and the app is activated the app immediately connects to the sensor, occasionally I have had to turn the sensor off and on again to initiated the connection.

At this point the sensor begins  warming up, reaching a temperature of 400 degrees Fahrenheit over a period of about 80 seconds.

The app displays the progress and offers you the option of answering some questions about how you are feeling and doing on the keto diet.

I often take my BP while this is going on. Sometimes I read the New Yorker. Frequently I listen to Radiohead (Climbing Up The Walls). It takes a while. Pay attention, though. You don’t want to miss your blowing window and have to repeat the process.

 

The app will give you a warning about 10 seconds prior to the time you need to blow. The graph to the right appears when it is time to blow and you can view the sensors output as it tracks the acetone it is seeing over the 10 seconds that you blow.

At the end of the blow you wait a few seconds, eagerly awaiting your score. Will you be in Ketosis?

 

Finally, your score is revealed. In this case I was congratulated for being in light ketosis with a fat burn of “medium high.” The highest score is an 8.

You can add notes to the record of your score

If you blow a 6 the app tells you that your fat burn is high and that you are in ketosis: “metabolizing fat like a champion.”

Accuracy of Keyto

When I first began using Keyto I checked the Keyto numbers versus the beta hydroxybutyrate (BOHB)  numbers I was simultaneously getting from my Keto-Mojo meter.

I found a Keyto 3 corresponded to 0.8 BOHB, a Keyto 4 to 0.9 BOHB, and a 5 to 1.0 BOHB.  That was enough to convince me that the device was accurate and useful in measuring my level of ketosis.

Given that it is so convenient compared to a finger stick I have stopped using the Keto-Mojo completely.

My observations confirm what Weiss and Ray Wu, MD, the cofounders of Keyto describe in very lucid prose here.

In extensive user testing, Keyto is directionally consistent with the more accurate commercially available blood meter. Keyto and blood β-hydroxybutyrate trend directionally the same in the majority of cases. Both go up and down in similar magnitude at different ranges of ketosis. There are some differences which are likely due to biology – the kinetics of clearance of acetone and β-hydroxybutyrate are not identical.

Some of the differences are also likely due to how we designed the Keyto program. Our primary goal was to develop a system that would give users the information they need to know i.e. if they are in ketosis, which would ultimately help promote healthy behavior change. Therefore, we chose not to report acetone concentrations in PPM or to attempt to convert PPM to blood β-hydroxybutyrate (mmol/L). The Keyto Level system was simply more effective, motivating, and fun without adding complexity and false precision.

I can make multiple measurements throughout the day without worrying about the cost or the discomfort of a finger stick. The ability to make multiple measurements means that I am getting very rapid and frequent feed back on how my dietary and lifestyle choices are effecting my level of ketosis.

Warning! Because the device is so convenient-literally you can have it with you at all times-you may find yourself blowing into it excessively. This may irritate your friends and loved ones, especially those that aren’t on a keto diet.

Keyto is Legitimate

The Keyto website has an excellent introduction to the keto diet (keto 101) and has numerous other very helpful resources for those who seek to lose weight using the diet.

In general I get a good feeling of integrity and legitimacy from every aspect of the Keyto operation.

I have a tremendous professional respect for Ethan Weiss, the cardiologist behind Keyto. He’s very active on Twitter and is typically spot on with his comments. He’s done a podcast with Peter Attia which serves as an excellent summary of atherosclerosis and coronary artery disease. He does really good basic science research involving growth hormone.

Weiss is now doing his own podcast called Best Known Method by Keyto which I highly recommend. It is not, surprisingly, focused on the keto diet or the keyto brand but interviews thought leaders in cardiology like Ron Krauss and Lisa Rosenbaum.

If you want to read more about how the Keyto breath sensor works see here. This is a very clear and concise description of the science behind the device and it is complete with references.

Ultimately, although I consider myself a keto-friendly cardiologist, I’m most interested in the diet that helps my patients achieve  and sustain their goals of weight loss and better health. For many this is the keto diet.

And for those who find the keto diet is optimal for their health I will be advising them to acquire a Keyto breath sensor and check out the programs Keyto offers to support their health goals.

Acetonely Yours,

-ACP