If an apple a day keeps the doctor away, then donuts may as well be a one-way ticket to the Grim Reaper. Let’s face it, after determining your daily intake through the IIFYM calculator, you may as well not even think about enjoying candy with some of those available macros, right?

Well, not so much… Despite how bad of a rap sugar consumption gets from mainstream media, the scientific community and their well-supported research show quite a different story. Before you vow to never tempt your taste buds with the sweet taste of that evil substance. Or, lock your kids away in an organic garden.

Below are some considerations and legitimate scientific research to shed light on what professionals in the nutritional science community are saying about sugar. We’ll also cover how sugar intake can and should be approached by using IIFYM for those looking to balance their performance goals with the enjoyment of daily life.

Before delving any further into the topic. It should be noted that throughout this article, “sugar” is used in reference to added sugar in prepared foods. It should also be noted that all carbohydrates, no matter how “healthy” eventually break down into the monosaccharide, glucose (which is sugar), before being used and stored by the body so technically all carbohydrates are eventually converted into sugars.

Dextrose (glucose), sucrose (table sugar), fructose (fruit sugar), and galactose (sugar in milk), and a synthetically derived form of sugar – high fructose corn syrup (HFCS) are common “sugars”. These types are the topic of conversation when health effects on sugar consumption are discussed.


For anyone that has been following my articles here on IIFYM.com. The topic of thermodynamics in relation to weight loss and muscle growth has come up more than once, and for good reason.

In an industry of misleading marketing, the idea of certain foods, workouts or supplements being magic bullets has inundated magazines, websites and locker rooms across the country.

No single aspect of training and nutrition will affect weight change more significantly than thermodynamics will- that is. The average balance of energy consumed compared to energy expended.

If you’re looking to lose fat, for example, myself, as well as the IIFYM coaching staff, can all assure you that cutting out any nutrient or food ingredient isn’t the answer to better health or physique (legitimate allergies aside).


The answer for long-term body composition changes lies in following a balanced, consistently tracked diet in which total daily calorie intake is gradually adjusted to create a sufficient caloric deficit for continued weight loss.

Restricting yourself to certain foods, or swearing away any one ingredient will just make the dieting process more difficult without any further benefit. All the more reason to look into a Macro Blueprint so you can drop the diet restriction while on a fat loss plan.

One coach’s word may not necessarily convince the masses, but having legitimate, scientific research to further back those principles can be a bit more persuasive. Over the past decade or so, scientists have spent considerable time and resources in researching the possible health effects sugar intake can have on humans.

During that research, some interesting findings have been found which can shed light on the not-so-villainous nature of sugar intake, and the benefit of an IIFYM diet plan.

What the Research Says

A 2007 study explored the effects of high glycemic vs. low glycemic based diets among 34 individuals, with all other dietary factors including dietary reference intakes of macronutrients and micronutrient, met, as well as a daily multivitamin. The study reflected no significant difference in body weight, body fat, and resting metabolic rate across a yearlong intervention (1).

Another study investigated the difference in weight loss among individuals consuming a high or low glycemic focused diet, that were able to following a structured energy restricted diet (planned weight loss program) by consuming 1,000 calories of their plan with foods they freely chose, compared to those within the study that followed a meal plan without individual food selection available.

There aren’t good or bad foods, but simply some foods that offer a higher nutrient profile, which should be added into a balanced diet for long-term health and proper performance.

The results showed no significant difference in weight loss for those freely consuming higher glycemic foods than those following a strict meal plan of low glycemic foods. Once again, food choice is shown to have far less effect on weight loss than total energy balance.

The one common factor, energy balance in both studies was accounted for and controlled regardless of the carb sources consumed (2). Sounds a bit like a successful IIFYM diet plan to anyone?

Quantity, Not Calorie Source

A separate, research review on countless past sugar studies also supports the conclusion that the excess calories, not the source of calories, is the main determinant of weight management (3). This said it’s much more reasonable to conclude that removing sugar from a diet doesn’t promote weight loss directly, but instead can help improve weight loss efforts by reducing excess calories.


Removing those 3 daily cans of soda from your diet and experiencing sudden weight loss isn’t from removing an evil liquid, but from reducing your caloric intake by roughly 2,940 calories per week (roughly 140 calories of sugar per soda can).

However, if a can of soda was a big craving of yours, and accounted for through an IIFYM approach to your daily caloric intake goals, it’s not going to harm your weight loss efforts (4).

This not only supports that sugar intake itself is unlikely to disrupt weight loss efforts but also supports the idea of IIFYM dieting.

There aren’t good or bad foods, but simply some foods that offer a higher nutrient profile, which should be added to a balanced diet for long-term health and proper performance.

“IIFYM allows individuals to apply scientific research to the challenges and enjoyment of everyday life”

Macro Make Up Does Matter

Sugar intake would only affect weight change if it were substituted for other macronutrients, namely protein.

Someone eating adequate protein, and consuming sugar in moderation within their total daily carbohydrate intake will make vastly different progress in body composition than someone not eating enough protein, but eating larger amounts of carbohydrates through added sugars.

If daily protein is sufficient, fat intake is adequate for optimal performance and hormone health, and total carbohydrate intake is appropriate for your current metabolic rate and weight loss goals. Then using IIFYM and having more or less simple sugars in your diet won’t derail your efforts.

Sweet Benefits of Sugar Consumption


Metabolic Capacity and Muscle Growth

When not dieting for fat loss, individuals should be focusing on improving performance in the gym through greater aerobic performance, strength, and/or larger muscle size- dependent on each person’s particular goals.

In order to do that, and also to ensure the future dieting phases are achieved as healthy and efficiently as possible, it’s important to gradually increase total food intake. This will support better recovery, better performance, and a greater metabolic capacity by allowing the body to adapt to and effectively use greater food intakes.

When doing this, many individuals avoid IIFYM and handicap themselves by trying to stick solely to “health foods.” By limiting sugar intake to a bare minimum, and eating only high fiber, high volume foods.

However if low-fiber, more sugary carb sources are ingested, individuals can maximize this glycogen replenishment and ensure optimal performance in subsequent bouts of exercise (8).

These individuals leave themselves bloated and unable to comfortably train at full capacity. At that point, they decide to stop increasing food intake and proceed through the rest of their growing season with a less than ideal offseason intake.

IIFYM can allow those individuals to reap the benefit of covering their bases through various fruits, vegetables, whole grains and unsaturated fats. Then utilize “fun” foods to supplement their daily food intake.

Leading to more comfortably reaching a higher intake that can more effectively help them maximize their efforts. By allowing themselves to enjoy some sugar-containing foods in their diet. They can improve digestion, train harder, feel better, and set themselves up for an even more efficient dieting phase in the future.

Intra-workout Performance

For those looking to maximize strength output and performance during exercise. Fast-digesting carbohydrates during workouts (in the form of carb powders), can help reduce fatigue and improve strength output during training sessions (5).

If you were to limit your sugar intake, at least having some sugars during your training sessions could be beneficial. By helping to maintain blood sugar levels during exercise.

Consuming a carb powder such as pure dextrose, a sports drink like Gatorade, or a similar carbohydrate supplement provides the body with readily absorbed glucose. Preventing that “bonked” feeling athletes often feel when training for extended periods of time without nutrients.


Post-Workout Glycogen Replenishment

Sugary foods can also be beneficial for consuming immediately after vigorous exercise as they support greater muscle glycogen restoration. They can help kick-starting recovery in the hours just after exercise. Although it isn’t necessary to pound sugar and a protein shake just after resistance training. It’s beneficial when focusing on replenishing glycogen before subsequent training sessions.

If you’re currently in a dieting phase when carbohydrate intake is low or an athlete that trains multiple times within a 24-hour time window. Such as multi-event competitions like Cross Fit often requires having some fast digesting carbohydrates at the cessation of a vigorous workout (1-1.5 hours).

Which can help significantly increase the rate of muscle glycogen replenishment before the upcoming training event.

This is due to two factors in particular; the first being that weight training itself promotes greater availability of a receptor within muscle tissue that takes up glucose for glycogen storage, GLUT-4.6.

The second contributing factor is that of the rate-limiting enzyme for glycogen storage, glycogen synthase, being greatly heightened just after resistance training (7).

If an athlete is consuming high-fiber, slower digesting carbohydrate sources, these benefits are hindered. However if low-fiber, more sugary carb sources are ingested, individuals can maximize this glycogen replenishment and ensure optimal performance in subsequent bouts of exercise (8).


All science rhetoric aside momentarily, it’s just as important to keep in mind the simple enjoyment of treating yourself to the foods you like. As much as eating for health and performance is important, so too is enjoying life.

One of the most beneficial aspects of an IIFYM diet plan is to stay on track with our health and physique goals. While still being able to periodically have the foods, we enjoy most.

The main aspect many “fitness professionals” leave out when promoting their 30-day challenge, or bashing IIFYM is the inability for the large majority of people to adhere to such restrictive diets over the course of their lifetime. Forever forsaking sweets, and sticking to bland foods may help with weight loss initially.

Yet, you are sure to create poor long-term relationships with food, and greater urges to binge eat on tempting foods. Learning to eat strategically with an adequate balance of nutrients, and occasional sweet treats can go a long way in promoting long-term body composition goals.

What about insulin spikes causing fat storage?

Ask people why they avoid sugar, and most respond with fears of spiking insulin. As hard as it may be to accept, insulin production itself doesn’t cause fat storage. Insulin will only promote fat storage if excess energy (calories) is consistently consumed- not simply by consuming sugars.

Instead, insulin first signals muscle and liver cells to store consumed sugar as glycogen to later be used as a readily available energy source.
Since muscle glycogen is quickly used as energy during exercise, and to a degree during daily activity and brain function.


This storage doesn’t attribute to body fat. When too much energy is consumed compared to what the body’s metabolism and training routine can accommodate for, those glycogen stores become full- and any “leftover energy” is then signaled to be stored within fat cells.

Ultimately, it’s eating too much (caloric surplus) that causes the extra fat gain, not the insulin spike.

In terms of increasing diabetes risk, this would again only occur in an environment where excess energy consumption is achieved on a constant basis over a somewhat extended period.

A 2005 study helped to explain this realization when a group of low-GI, high-GI or high fat based dieters all lost nearly the same amount of weight and improved insulin sensitivity.

In practical terms, whether a diet is restrictive and only focused on low-GI “health” foods. Or includes some high-GI “fun” foods as part of an IIFYM dieting approach. Both fat loss and improved insulin sensitivity can be achieved with nearly identical results (9).

Insulin and Diabetes Risk

In terms of increasing diabetes risk, this would again only occur in an environment where excess energy consumption is achieved on a constant basis over a somewhat extended period.

For Type 2 Diabetes to occur, it is largely due to a culmination of lifestyle factors, and not simply sugar consumption. Body fat level, total energy balance, exercise, and genetic predispositions are some major factors that play into the risk of diabetes.

For anyone considering following an IIFYM diet plan but concerned with Type 2 Diabetes risk. Avoiding sugar on nutrition labels isn’t necessarily the answer. Instead, there are other lifestyle practices that will vastly reduce the chance of occurrence. Shown to greatly benefit insulin sensitivity (ability for the body to use a given amount of insulin effectively), thus helping prevent diabetes:

• Regular exercise in the form of both resistance training and aerobic activity. Moderate to vigorous exercise has been shown to greatly improve insulin sensitivity (10,11).

• Maintain a healthy body weight. Insulin sensitivity is shown to improve as body composition improves (muscle to fat ratio) while being overweight tends to reduce the ability for the body to properly use insulin.


• When body fat levels begin to get too high, performing brief diets, often termed “mini cuts,” can help regain proper insulin sensitivity. Showing that periodic diets are not only good for improving appearance but improving the efficiency of the body’s hormones (12).

• When possible, have your major carbohydrate containing meals before and after training sessions. Doing so takes advantage of heightened insulin sensitivity and greater storage of carbohydrate as glycogen rather than body fat.

In terms of increasing diabetes risk, this would again only occur in an environment where excess energy consumption is achieved on a constant basis over a somewhat extended period.

Whether a person consumes excessive amounts of organic oats through a meal plan or packaged oatmeal pies with IIFYM. They can both create extreme, chronic rises in insulin and eventually lead to increased diabetes risk.

“Properly incorporated IIFYM diet plan strategies not only support physique goals, but also long-term health”

But sugar causes inflammation, right?

As we wrap up our discussion on sugar, and its often-over-exaggerated role in fat gain. It’s important to briefly touch on the correlation between sugar intake and increased inflammation.

Although there does seem to be a possible link between increased sugar intake and increased inflammation. It should be noted that this link is often shown in individuals whom regularly consume a higher than the reasonable daily amount.

Many research populations also neglect other lifestyle factors important for keeping inflammation within a healthy range.

Of the studies currently published researching the connection. A great majority are on a sample population not documented to be correctly performing many, or any, of the related lifestyle habits shown to minimize inflammation (13,14).

• Consuming a variety of fruits and vegetables, which contain many anti-oxidants and phytonutrients essential for reducing inflammation.

• Regularly consuming Omega-3 fatty acids through sources like fatty fish and fish oil supplements. Maintaining a proper intake of Omega-3 fats within the diet, and limiting excess Omega-6 fatty acids has been strongly supported by research to reduce inflammation (15,16).

• Performing regular exercise. Along with increasing insulin sensitivity and carbohydrate storage efficiency. Regular resistance training is also shown to provide long-term anti-inflammatory benefits. Although resistance training does create a short-term, inflammatory response as muscle tissue recovers from the exercise session. It’s actually short-lived, and still, has extended lasting anti-inflammatory effects (17).


Let’s Not Forget

Although IIFYM minded coaches such as ours discourage the fear of sugar consumption. We never dismiss the importance of a varied, nutrient filled diet.

Although somewhat speculative, it would seem reasonable to believe the results of many sugar & inflammation studies would be less drastic if factors like those mentioned above were accounted for while focusing on nutrient-dense foods was also implemented in each individual diet.

Sugar in reasonable amounts doesn’t seem to create any long-term negative health or body composition effects. However, it would be asinine to say sugar can be safely consumed in unlimited amounts.

We can all agree that too much fat can contribute to heart disease and too much protein can lead to gastrointestinal discomfort. Although excess consumption can create issues, no reasonable person would deny their importance in a healthy, performance-supporting diet.

Just as protein and fat should be consumed within reason, sugar should be avoided in excessive amounts in order to maintain proper inflammatory responses, energy balance, and allow for sufficient intake of more nutrient-dense foods within daily intake goals.

So how much sugar can I eat?

After hearing that total energy balance is the prominent factor in weight change, IIFYM extremists will take that and run with it- eating as many cookies and ice cream cones as they can fit into their daily macro goals.

However, that strategy is just as detrimental to long-term progress, and possibly more so to health, than avoiding sugar altogether.

Although sugar consumption in moderation is unlikely to cause any negative effects, balance is still vitally important. This is always encouraged when our coaches create Macro Blueprints for our clients!

How much is too much? Keeping a daily fiber intake goal can be a great strategy for limiting sugar intake to a reasonable level. Also, ensuring that enough nutrient-dense foods are consumed.

Following the below, USDA provided fiber and sugar intake goals can go a long way in keeping intake balanced and healthy.

Don’t Forget the Fiber

Fiber has been shown to provide numerous health benefits include disease prevention, nutrient absorption, digestion, healthy blood sugar maintenance, and improving satiety which is especially helpful when dieting (18).

Just as too much fiber can cause issues like those discussed earlier in this article, so too does too insufficient fiber have drawbacks.


The USDA suggests most individuals consume 14 grams of dietary fiber for every 1,000 calories consumed in their diet (i.e. 39 grams for a daily intake of 2,8000 calories).

Consuming this fiber recommendation through a variety of sources promotes sufficient micronutrient intake, given foods such as fruits, vegetables, and whole grains are great sources of fiber, and also contain substantial amounts of vitamins, minerals and antioxidants important for long-term health, and optimal physical performance.

Sugar Recommendations

The American Heart Association and USDA recommend that men consume no more than 150 calories (38 grams) and females consume no more than 100 calories (25g) of added sugars per day in order to greatly reduce any potential health risks. For reference, some common foods and their accompanying sugar content are listed below.

Sugar Content in Common Foods

Food Type/BrandQuantity/VolumeSugar Content (grams)
Maple Syrup1 Tablespoon14
Full Calorie Soda 1 Can39
Twix Candy Bar1 Package28
Glazed Donut 1 Donut11

So, as you can see by just these few examples. Healthy individual sticking strictly to these suggestions could theoretically still enjoy a can of soda or donut a few times each week through IIFYM and still be within a reasonable intake.

Although the intake suggestion can be a safe recommendation to follow. It would stand to reason that trained athletes following IIFYM can likely consume higher amounts through intra- and post-workout carbohydrate intake without creating any health issues.

Since those sugars are more likely stored as glycogen than body fat. Plus, an otherwise nutrient-dense diet is likely to reduce the risk of negative health effects from higher sugar consumption.

“Using IIFYM to periodically enjoy sugary foods can be part of a healthy, life-long nutritional strategy”

Sweet News

This article isn’t to encourage people to use IIFYM as a free-for-all but does explain that like most happenings in life. It’s okay to enjoy sugar in moderation. Taking anything to a restrictive or gluttonous extreme seldom turns out well for people in the long run.

Yet, making a point to educate ourselves on the facts behind our concerns. While learning how to properly apply those facts to our daily lives can go a long way progressing as efficiently as possible while making room to enjoy life. Now, where are those donuts I bought?