By Dr. Mike Israetel, Professor of Exercise Science at Temple University

Editor’s note: This article is about drawing the line in the search for honest reporting on weight gain, fat loss, and the growing concern about “belly fat.” It was originally scheduled to be published on a mainstream media site. But one editorial request for clarity turned into another for additional research, turned into a game with one agenda: no desire to post an article that clearly opposes a vested interest in a popular book.At Born Fitness, we have one agenda: look at information objectively, translate information, and help you figure out how to apply it to your life. This post is an honest, balanced review on popular diet methods, or as most people think of it: how to lose belly fat. That’s why we worked with Dr. Mike Israetel, a professor of exercise science at Temple University, to review what science really reveals about weight loss, and challenges a popular opinion on weight gain. Whether you agree or disagree with the ideas and research shared, it’s important that open discussion is not censored. -AB

Most studies simply do not demonstrate a detectable effect of the glycemic index on weight gain or loss.

In a recent interview with the New York Times, Harvard nutrition professor Dr. David Ludwig previewed some of the basics of his new book, Always Hungry, which proposes a solution to the problems of obesity that plague much of the western world today.

While many of his ideas seem rational and justified, too much of his thinking seems to run counter to the best current understandings of most other experts in the field of nutrition, health, and obesity. Here’s an inside look at Ludwig’s claims based on his New York Times article, and what we know about weight gain and fat loss. 

The Glycemic Index and Weight Loss: The Broken Model

The claim: “In his new book, “Always Hungry?” Ludwig argues that the primary driver of obesity today is not an excess of calories per se, but an excess of high glycemic foods like sugar, refined grains, and other processed carbohydrates.”

Behind the Science: There are several problematic elements with the claim that high glycemic index (GI) foods are mostly to blame for current obesity rates. The most straightforward are that multiple peer-reviewed research trials on the effects of low vs. high glycemic index foods on weight loss have shown that results are similar.

While some studies show that high GI foods affect weight loss negatively and might help cause weight gain, most of the studies show no such effects. That’s right, most studies simply do not demonstrate a detectable effect of the glycemic index on weight gain or loss.

Even if we assume that high GI foods are a big part of the problem, this leaves most of our worst criminals on the streets, so to speak. Cookies, ice cream, pizza, burgers, shakes, potato chips and candy bars are almost all low GI foods. How can this be with all that sugar and those processed carbs they are loaded with?

You see, the presence of fat lowers the glycemic index of any food. The more fat, the lower the GI, even if there’s lots of sugar too.

That’s why brown rice has a GI of about 50 (out of 100), but premium ice cream can have a GI under 40. Are we really ready to claim that brown rice is worse for obesity than ice cream? If we accept one of the central concepts of the “insulin hypothesis” as undeniable, then we have to apply the principle equally for all foods, meaning ice cream is good for weight loss.

The truth is, the relationship between insulin, the glycemic index, and obesity is complicated, but also overstated. Without an excess of calories, all the high-GI food in the world won’t make you fat.

That’s not to say insulin isn’t a contributing factor to weight loss and weight gain. The study of obesity has made it very clear that it’s a complex disease.

There might be a small role for insulin to play in contributing obesity, but something being a small contributor is not nearly the same thing as it being the primary cause. It’s much more likely that tasty, high-calorie foods, such as ice cream, are just much easier to overeat than unprocessed or naturally sweetened foods, and that’s a primary reason why diets high in junk food cause weight gain

Metabolism and Calories-In, Calories-Out

The claim: “Simply cutting back on calories as we’ve been told actually makes the situation worse. Our body responds by increasing hunger and slowing metabolism.”

Behind the Science: It’s absolutely true that cutting back on calories slows your metabolism and can increase hunger. But slow (1% weight loss per week) and steady reductions in eating, combined with increases in activity and exercise have a very small effect on increasing hunger and slowing the metabolism.

In fact, consider the following scenario to help understand weight loss, and how food selection is not the only way to create change.

Let’s say you take someone who is 250 pounds and have them lose 10 percent of their weight and then completely take a break for their fat loss plan. In this scenario, the person would now be 225 pounds after a few months on a plan.

After the break, the subject’s metabolism would speed back up to its normal levels for their current body weight and hunger cravings would return to normal.

This re-setting of the body weight set point is something Ludwig discusses, but it can be done with planned weight loss breaks, and not just with glycemic index reduction and special food selection. None of this is very controversial in the study of obesity.

The big question is: how do we keep people at that new weight or perhaps even get them lower?

Research has shown that after people leave weight loss studies and are no longer monitored or told what to eat, most (in many cases exceeding 90%) will return to their previous weights over time, and many will go up even higher.

And here’s maybe the most important consideration: this happens with essentially every single kind of diet that’s ever been studied, and low glycemic “natural foods” diets are no exception.

Left to their own devices, most obese people will get right back to making the kinds of choices that lead to weight regain.

The big question in obesity research is not how to lose weight…that we know. It’s how to keep it off in the real world, even without special metabolic slowdowns or hunger cravings to account for.

Blood Sugar and Weight Gain

The claim: “We think of obesity as a state of excess, but it’s really more akin to a state of starvation. If the fat cells are storing too many calories, the brain doesn’t have access to enough to make sure that metabolism runs properly.”

Behind the Science: Overweight and obese people have higher, not lower levels of blood sugar and higher, not lower levels of blood lipids, even when they’re fasting. To say that the brain is lacking in nutrients in those with higher body fat levels is not simply to make a misstatement or an exaggeration, but it’s the exact opposite of the truth.

The Yo-Yo: Fat Loss and Weight Gain

The Claim: “Put biology on your side by eating the right way, and weight loss will occur naturally as a fever would break if you treat the underlying cause of the fever.”

Behind the Science: Within this statement is a claim. The claim is that if you do things the right way, you’ll lose weight easily and effectively, and your life will change for the better.

The problem is that while it’s true for the kind of diet Ludwig supports, but it’s also true for almost every other kind of diet ever tested. So long as the diet reduces daily calorie intake, weight loss occurs.

The big problem is that such weight loss, again, from nearly all diet types, doesn’t seem to be very sustainable in the real world by real people over the course of months and years after the weight loss has occurred. There is no evidence to suggest that Ludwig’s proposed low GI whole foods diet does any better of a job retaining losses in the long-term than most any other diet that’s been studied, including low-fat, low-carb, low-sugar, or the “you-name-it” diet.

The Best Diet: Belly Fat, Low-Carb, and Low-Fat

The Claim The underlying cause of obesity is not obesity…“It’s the low fat, very high carbohydrate diet we’ve been eating for the last 40 years, which raises levels of the hormone insulin and programs fat cells to go into calorie storage overdrive.”

Behind the Science: There is a very big problem with this statement. The problem is that Americans have not been consuming a low-fat, very high-carbohydrate diet for the last 40 years.

Average levels of fat intake have been about the same over that time for the average American, it’s just that carb intake went up so much more.

Yes, various national governing bodies on nutrition and health have advised Americans to eat less fat and more grains over this time frame. But it seems Americans only heard part of that message and just added the carbs but never reduced the fats!

To say that Americans eat a low fat diet is simply not true by any definition of what “low fat” really means. What Americans have been doing is eating many more calories, and that’s a sure way to gain weight no matter where those calories come from.

Another potentially erroneous conclusion that could be drawn from this statement is that low fat, higher carbohydrate diets have been reliably shown to lead to weight gain as opposed to higher fat, lower carbohydrate diets. This is not remotely the case.

Vegans and vegetarians, for example, consume far higher amounts of carbohydrates and far lower amounts of fat than omnivores, yet are on average much less likely to be overweight or obese. It’s just not true that those who eat more carbs and fewer fats are fatter people… though those who eat more calories are, no matter how they get them in.

Upgrading Your Diet

Dr. Ludwig’s views are not totally at odds with the current status of the scientific literature. In fact, his approach has quite a few potentially healthy and effective elements.

High-glycemic foods might have some role in keeping hunger levels higher for the same calories as low glycemic foods. However, high GI foods are not always low in satiation power and vice versa.

There is an independent and more useful measure of a food’s direct effect on hunger, called the Satiety Index, and it doesn’t always mesh with the glycemic index. For example, white potatoes are very high on the GI-ranking but are one of the most satiating carb sources.

Whole foods tend to have much higher levels of vitamins, minerals, phytochemicals and fiber than processed foods, making them healthier choices regardless of your body weight. They are also usually much more satiating for the same amount of calories, so over-eating is going to be more difficult.

Think about it: How many potato chips can you eat? What about slices of fresh apples? How many people have eaten enough potato chips to gain unwanted weight? What about slices of apples?

By eating highly nutrient dense foods that have more powerful effects on making you full and keeping you full, you stand a higher chance of losing weight and keeping it off. Fundamentally, the basic causes of the modern obesity epidemic are:

• The increased mechanization of the workforce, leading to less physical activity at work for most people, and thus fewer calories burned per day on average
• The increased wealth of the average person, especially in relationship to food costs. Today, even some of the poorest Americans can afford enough calories to gain weight, and this was not always the case historically.
• The improved taste and availability of food. Packaged, processed, ready-made and fast foods bring tons of tasty food to your mouth quick. Historically, if you wanted tasty food, you had to make it (which took time and effort) or wait for someone to make it (which took either time, lots of money, or both). More and more over the past several decades, tasty food has become cheaper and more easily accessible. Eating tasty foods is easier than ever.

Less activity to burn calories, more affordable food to buy and the food is more convenient and designed to be tastier than ever. Is it any surprise we have more people searching for “how to lose belly fat” and struggling for a solution to the obesity epidemic?

Delicious food has been shown to cause more cravings for delicious food, as this detailed research describes. The problem with short-term weight loss is that most people will go back to making the same choices for tasty foods that they were making before they followed a weight loss diet. These choices will lead to more eating, and calorie intakes go up once again to previous levels.

In order to put a real dent in the obesity epidemic, controlling cravings may be a powerful weapon. But in his proposed solution, Dr. Ludwig demonizes and targets a false enemy in glycemic carbohydrates. Yes, limiting them might be a part of the way forward, but rhetoric suggesting that calories don’t matter for weight loss doesn’t serve any beneficial purpose.

Ultimately, (barring a pharmaceutical cure) successfully countering weight gain and obesity and is a combination of many nutrition and behavioral principles that keep the fundamentals (like calorie balance) in mind. Catch-phrase demonization of a single nutrient and a magic-bullet cure is unlikely to ever be the solution, and–in fact–more likely to create more problems and confusion about how to fight obesity.

READ MORE: 

Big Meals vs. Small Snacks: What’s Best For You?

Faster Fat Loss: How to Add Workout Finishers

How Many Eggs are Safe to Eat?

Adam Bornstein

Adam Bornstein is a New York Times bestselling author and the author of You Can’t Screw This Up. He is the founder of Born Fitness, and the co-founder of Arnold’s Pump Club (with Arnold Schwarzenegger) and Pen Name Consulting. An award-winning writer and editor, Bornstein was previously the Chief Nutrition Officer for Ladder, the Fitness and Nutrition editor for Men’s Health, Editorial Director at LIVESTRONG.com, and a columnist for SHAPE, Men’s Fitness, and Muscle & Fitness. He’s also a nutrition and fitness advisor for LeBron James, Cindy Crawford, Lindsey Vonn, and Arnold Schwarzenegger. According to The Huffington Post, Bornstein is “one of the most inspiring sources in all of health and fitness.” His work has been featured in dozens of publications, including The New York Times, Fast Company, ESPN, and GQ, and he’s appeared on Good Morning America, The Today Show, and E! News.

The post Challenging the Belly Fat Hypothesis appeared first on Born Fitness.

ASK BORN: How many carbs and protein should I be eating post-workout? You like waixy maize? –Max

When I first started training, there was nothing I looked forward to more than my post-workout meal. It was the time when my muscles were starved for food. But more importantly, I thought it was a time when my body needed a massive insulin surge to take carbs and transform them into hard earned muscle.

What you eat after a workout is less important than meeting your overall calorie and macronutrient guidelines for the day.

In my mind, insulin meant sugar, and sugar meant Frosted Flakes. (And lots of Frosted Flakes, as in several very large bowls.) After all, I was convinced my body was like a sponge after a workout and would soak up all the carbs.

Turns out, my mindset regarding the need for significant carbs after a workout was misguided. Of all the ingredients involved in building the body you want, there’s a certain mystique about the role and importance of the meal you enjoy after your workout.

There’s no shortage of information and opinions on what you should eat, how much you should eat, the importance of the timing, and the dangers of what you risk by not emphasizing this meal. And while timing is not insignificant, the latest research indicates that most what we thought was true about the post-workout meal no longer holds as much accuracy.

One of the most common suggestions revolves around the consumption of carbs after your exercise session. While consuming carbs after a workout is perfectly fine—and carbs are necessary for muscle growth—our bodies don’t need as many carbs as we think. More importantly, we don’t need to load up on simple carbs (think sugar) in order to refuel and see changes.

The New Rules of Post-Workout Meals

The biggest problem with focusing on what to eat after your workout is that we tend to view this meal in isolation. Instead, it’s best to be aware of what you had before your workout, or if you train in the morning, what you had for your last meal before you sleep.

Your body doesn’t run on a short-term fuel supply. Your glycogen (muscle energy, if you will) is filled up anywhere between 350 to 500 grams of carbohydrates. If those numbers don’t mean much to you, that’s more than enough fuel to get you through your weight training workout; and plenty for most endurance sessions, too.

Your goal is to promote muscle protein synthesis (muscle growth and repair), and for that to happen, you don’t need a massive insulin spike. In fact, research has shown that a moderate amount of protein and carbs (or even protein alone, more on that soon) can max out the muscle protein response after exercise.

In this study, scientists found that insulin is “permissive rather than stimulatory.” Instead, it’s to make sure you activate insulin and allow it to do its job.

Translation: the goal isn’t to jack up insulin to see a greater response.  More carbs and insulin is not better and does not accomplish more.

Pre-Workout v.s. Post-Workout: A Team Approach

This certainly differs significantly from the general ideology passed down from some supplement companies. The commonly held belief is that if you don’t use fast-acting carbs immediately after a workout, then you won’t elevate your insulin levels, you won’t recover, your body will shrink, and all potential gains will be lost.

Your body isn’t carb-dependent because post-workout because you ate before your workout can have a big impact.

In fact, a pre-exercise meal can help ensure that your insulin levels remain elevated up until your workout is over. If you eat protein and carbs before you train, insulin can remain elevated for several hours. And if you don’t like solid foods, combining 6 grams of essential amino acids with about 35 grams of carbohydrates can keep insulin levels about four times higher than fasting levels for about two hours.

This isn’t to tell you must eat before you train (it’s completely goal dependent and also a matter of how well you digest food before you exercise).

Instead, it’s to emphasize how easy it is to create an insulin response that will help your body before, during, and after training. And more importantly, it allows you to know the flexibility involved in choosing what you eat before or after a workout without having to worry that you must follow a specific plan that might not feel right for you. (This is something I’ve tested with clients and have found to be much more beneficial than rigid plans.)

Insulin’s ability to prevent muscle protein breakdown and maximize muscle protein synthesis isn’t dependent on massive amounts of carbs (because you’re not completely depleting your glycogen stores), and doesn’t require a special carb blend.

This is another instance of people majoring in the minor. The, “I need magical fast-acting carbs from waixy maize within 30 minutes of training” is not as important as focusing on the bigger picture. In this case, making sure you have some protein and carbohydrates after a meal, and focusing on a good overall diet.

Whereas many people believe that the 5 percent is where winners are made, it’s really where the most stress occurs, arguments erupt, and progress can stall.

Master the big picture details first, and you’re likely to see more results, have better compliance, and achieve much better clarity. Then you can tackle the most specific details.

What You Should Eat Post-Workout

The urgency of a post-workout meal is significantly exaggerated. Moreover, most research with glycogen depletion and repletion focuses on endurance athletes. If you’re a runner putting in serious mileage, for instance, your need for glycogen-replenishing carbs is greater but still not urgent—and it’s on both ends of the spectrum.

Most people who have exercised are familiar with the concept of carb-loading. And yet, research published in the Journal of Applied Physiology found that bumping up carbohydrates to more than 50 percent of their diet (and maxing out at 75 percent) didn’t improve muscle glycogen and only led to a minor 5 percent improvement in their performance. In other words, all those extra carbs are not worth it. (Although the meals might be enjoyable.)

When it comes to weight training, your body is in even less of a need for the instant carb surge. That’s because most weight workouts—even the more aggressive approaches in the 45 to 60 minute range—won’t come close to depleting your glycogen stores.

And if you do eat a preworkout meal, that need is even less as the food you ate beforehand is most likely still being absorbed by your body even after you’ve finished.

What’s more, even if you don’t eat carbs before a workout and skip them in the time period immediately after you train, as long as you eat carbs several hours later your body will still recover and glycogen resynthesis will occur within about 24 hours. (Yes, the body is an amazing machine.) Consider this good news as the benefits of the post-workout meal period are experienced for a longer period of time.

The majority of the most recent research emphasizes that timing is less important than the total amount of food you eat, and the macronutrient ratios (of proteins, carbs, and fats) you consume.

That’s not to say eating after a workout isn’t important; rather, “after a workout” is just a much longer period of time than originally thought. In fact, the idea of the “small anabolic window” is minimized with each passing year (this is not a bad thing).

It now appears that your post-workout window is really open for about 24 hours rather than 30 to 60 minutes, with the first 4 hours being when you want to make sure you eat or have a shake. 

That means more flexibility with your meals and not feeling forced to slog down a shake if you’re not hungry.

Just as valuable is the research that suggests the increasing importance of protein after your workout. A study published in 2010 found that adding carbs (about 50 grams) to 25 grams of whey protein did not increase post-exercise protein balance compared to the protein without carbs.

As for carbs? Unfortunately the research just isn’t as clear. This excerpt is from a research review in the Journal of the International Society of Sports Nutrition on nutrient timing published by Alan Aragon and Brad Schoenfeld.

It is tempting to recommend pre- and post-exercise carbohydrate doses that at least match or exceed the amounts of protein consumed in these meals. However, carbohydrate availability during and after exercise is of greater concern for endurance as opposed to strength or hypertrophy goals.

Furthermore, the importance of co-ingesting post-exercise protein and carbohydrate has recently been challenged by studies examining the early recovery period, particularly when sufficient protein is provided. Koopman et al 52 found that after full-body resistance training, adding carbohydrate (0.15, or 0.6 g/kg/hr) to amply dosed casein hydrolysate (0.3 g/kg/hr) did not increase whole body protein balance during a 6-hour post-exercise recovery period compared to the protein-only treatment….

For the goal of maximizing rates of muscle gain, these findings support the broader objective of meeting total daily carbohydrate need instead of specifically timing its constituent doses. Collectively, these data indicate an increased potential for dietary flexibility while maintaining the pursuit of optimal timing.

Lab to the Kitchen: Designing Post-Workout Meals

What does it all mean? There is no “perfect meal” for after your workout. While the post-workout time period is still important and valuable, when it comes to achieving your goals, what you eat after (or even before) a workout is less important than meeting your overall calorie and macronutrient guidelines for the day.

If you are someone who tracks calories or macros, your daily goals should be focus 1A and 1B. In general, days where you train you should eat more carbs, and days when you don’t train you’ll most likely have less.

From there, determining what to eat post-workout depends on your preference. If eating pre-workout leaves you feel groggy or sick to your stomach, some branched-chain amino acids or potentially fasting (research has shown that protein breakdown is elevated after fasting and eating after training while fasted can have a positive effect; or if you don’t fast not eating 3 to 4 hours before your workout can be beneficial because a meal of protein and carbs can keep amino acid levels elevated for up to 6 hours) might be best for you.

But if you still need more direction for your post-workout meal, your top priority is probably protein. That’s because research shows that if you eat protein any time around your workout (before, during, after) then you have a similar increase in muscle protein synthesis.

Anywhere between 20 and 40 grams of protein before or after (or both) should do the trick, and based on Aragon’s research, a similar amount of carbs should work—although the science is not as definitive.

If you’re worried about eating fat in your post-workout meal, well, don’t. The idea that post-workout fat will slow down an “anabolic effect” of protein is unsubstantiated in any research. While protein and carbs are still the preferred nutrients, having some fat (think eating eggs) is not going to slow your process.

What you eat during the course of the day matters more than what you eat before or after your workout. In the post-workout meal prioritize protein over carbs, and when adding carbs understand there’s no need for massive amounts to raise insulin. This is not an anti-carb approach. Instead, it’s a matter of realizing the lack of urgency for carbohydrates post-workout, and understanding that you don’t need to consume excess amounts of carbs to recover properly.

Personalize Your Fitness Plan

Want more help figuring out what to eat and when? You can receive customized training and diet planning through the Born Fitness online coaching program.  

READ MORE: 

Fix Your Diet: Understanding Proteins, Carbs and Fats

Winning the War on Hunger: Practical Solutions to Overeating

How Much Fat Should I Eat?

Adam Bornstein

Adam Bornstein is a New York Times bestselling author and the author of You Can’t Screw This Up. He is the founder of Born Fitness, and the co-founder of Arnold’s Pump Club (with Arnold Schwarzenegger) and Pen Name Consulting. An award-winning writer and editor, Bornstein was previously the Chief Nutrition Officer for Ladder, the Fitness and Nutrition editor for Men’s Health, Editorial Director at LIVESTRONG.com, and a columnist for SHAPE, Men’s Fitness, and Muscle & Fitness. He’s also a nutrition and fitness advisor for LeBron James, Cindy Crawford, Lindsey Vonn, and Arnold Schwarzenegger. According to The Huffington Post, Bornstein is “one of the most inspiring sources in all of health and fitness.” His work has been featured in dozens of publications, including The New York Times, Fast Company, ESPN, and GQ, and he’s appeared on Good Morning America, The Today Show, and E! News.

The post The Meal Timing Myth? appeared first on Born Fitness.