Who is the lead author or research group?
Alan Aragon is the lead author for this position stand. He is internationally respected in the areas of diets and body composition. All the co-authors are equally well respected. In fact, the authors conducted much of the original research reviewed for this position stand.
Type of Research:
A consensus of expert opinion from the leading researchers around the world on diets and body composition.
Rigour of research (pros and cons)
Only prospective randomised control trials of more than four weeks’ duration were reviewed. Four weeks is the minimum amount of time required to observe any meaningful change in body composition. This prevents bias from studies of short duration, or with poor quality methodology. Where possible the data was pooled to allow greater certainty in the recommendations.
All authors reviewed the position stand before publication. This reduces the risk of individual reviewer bias, or any author stretching the recommendations past what the actual research shows.
This position stand is an essential read for anyone interested in diets and body composition. Reading this will provide the most up to date summary of current knowledge. It will literally save you hundreds of hours’ research.
PG – Phil Graham
JP – John Pemberton
a) Very-low- and low-energy diets (VLED and LED)
b) Low-fat diets (LFD),
c) Low-carbohydrate diets (LCD)
d) Ketogenic diets (KD)
e) High-protein diets(HPD)
f) Intermittent fasting (IF).
JP: It is important to think of dietary approaches in the above categories, rather than individual brands such as Atkins, South-beach, Paleo.
Many people get emotionally attached to a branded diet because they like the author, or the diet book is written in a seductive way. By using these dietary categories that are based on principles, it is possible to stay neutral and critically assess the evidence for and against the principles.
PG: The categories allow individuals to emotionally detach from the author or personality promoting a specific dietary approach.
Many people follow diets blindly without understanding their underlying mechanisms or principles. Atkins, Paleo etc.
These diet archetypes provide clarity and evidence-based understanding of how certain diets work.
2. All body composition assessment methods have strengths and limitations. Thus, the selection of the method should weigh practicality and consistency with the prohibitive potential of cost, invasiveness, availability, reproducibility, and technical skill requirements. Ultimately, the needs of the client, patient, or research question should be matched with the chosen method; individualization and environmental considerations are essential.
a) Methods range from 2C (two compartments) to 4C (four Compartments):
i) 2C: Fat Mass (FM) and Fat-Free Mass (FFM).
ii) 3CL FM, Total Body Water (TBW), and non-fat solids.
iii) 4C: FM, TBW, Total Body Protein (TBP) and Bone Mineral Content (BMC).
b) The more compartments the greater the accuracy, but the more expensive and harder to access.
c) The key is to ensure consistency to prevent the following issues invalidating the measurement:
i) Changes in glycogen levels.
iii) Time of day.
d) Table 1 on page 4 of the research document lists all the methods, their pros and cons.
JP: It is important to think why you are measuring body composition. If you want a good looking body, using weight and a visual assessment is more than adequate.
It is the visual aspect you want, not some arbitrary level of body fat. Weight and visual assessment by photos is the best method for 95% of the population.
Detailed body composition measurement can be useful:
Some key points to consider when choosing a method:
Avoid using a conversion table to calculate body fat percentage because the population used to determine that body fat percentage is unlikely to be similar to you. Just focus on reducing the total number of millimetres for progress.
The most important outcome for anyone following a set diet or training regime is how they look.
Unless you’re involved in a body composition experiment, no one is ever going to ask you…
Q. What body fat percentage are you?
Q. What percentage of lean mass are you?
Q. What was your umbilical skin fold?
Body composition measures are useful, but they can be highly inconvenient, expensive and open to large errors, especially the skin folds and the scales.
You can save yourself a lot of time, money and frustration by asking yourself these 4 questions on body composition progress.
Do you look leaner? = A clear sign of body fat is lowering.
Are my clothes looser? = Another sign body fat is lowering.
Are you stronger? = A key sign muscle mass is increasing.
Are people commenting on your progress? = They will if your body fat is dropping.
If you answered yes to all the above, you do not need to weigh on the scales or spend money on body composition testing.
3. Diets focused primarily on FM loss (and weight loss beyond initial reductions in body water) operate under the fundamental mechanism of a sustained caloric deficit. This net hypocaloric balance can either be imposed linearly/daily or non-linearly over the course of the week.
a) The higher the baseline FM level, the more aggressively the caloric deficit may be imposed. As subjects get leaner, slower rates of weight loss can better preserve LM, as in Garthe et al.’s example of a weekly reduction of 0.7% of body weight outperforming 1.4%. Helms et al. similarly suggested a weekly rate of 0.5–0% of body weight for bodybuilders in contest preparation.
JP: Before going any further, burn this universal truth into your brain.
“Fat loss is driven by a sustained caloric (energy) deficit.”
You may have a preference for a certain diet type because you find it easy to adhere to, or it suits your diabetes control. But do not be fooled into thinking that one diet has some magical advantage, it does not! If you achieve a consistent caloric deficit, you will lose weight on any diet type. You will see that this point is reiterated many times, that is purposeful because it is the most important principle of diets and body composition.
One important point to consider is your current weight status, are you overweight or lean?
PG: Calories are king.
All fat loss diets work off the same principle, controlling calories and generating an energy deficit.
There are a wide range of diets out there. They all work. It’s simply a matter of finding one that suits your personal preference for macros (carbs, protein, fat), nutrient timing and one that supports good blood glucose control.
The more body fat you carry, the more aggressive you can be with your calorie drop. A large portion of your initial fat loss will be body water, muscle glycogen and fat. Strength training will complement any deficit you impose.
The leaner you are, the slower and more tactful you need to be with your calorie reductions to safeguard muscle mass.
4. Although LM (Lean Mass) gains have been reported in the literature during hypocaloric conditions, diets primarily focused on LM gain are likely optimized via sustained caloric surplus to facilitate anabolic processes and support increased training demands. The composition and magnitude of the surplus, the inclusion of an exercise program, as well as training status of the subjects can influence the nature of the gains.
a) Larger caloric surpluses are more appropriate for untrained subjects who are primed for more dramatic progress in LM gain and for those with a high level of NEAT (Non-Exercise Activity Thermogenesis).
b) On the other hand, smaller caloric surpluses are appropriate for more advanced trainees who may be at a higher risk for undue FM gain during aggressive hypercaloric conditions.
c) It should be noted that not all trainees will fit within this general framework. Some novices might require smaller surpluses while some advanced trainees will require larger surpluses in order to push muscular gains forward. It is the job of the practitioner to tailor programs to the inevitable variability of individual response.
JP: If you are starting resistance training, or consider yourself as a “hard gainer”, you will benefit from a larger energy surplus per day, 200-300kcal per day:
If you are an intermediate to advanced trainer, you will need a smaller energy surplus per day:
PG: The older your training age, the more fine-tuned and tactful your calorie surplus needs to be. Generally speaking, individuals with 2+ years of consistent training experience should aim to consume a calorie surplus of 50-200kcals per day.
The less experienced you are, the greater your calorie surplus can be. Generally speaking, 200-300kcals per day is a good starting point for newbies and novices.
The most important consideration before you commence any mass gain phase is being lean enough to start with.
5. A wide range of dietary approaches (low-fat to low-carbohydrate/ ketogenic, and all points between) can be similarly effective for improving body composition, and this allows flexibility with program design.
a) To date, no controlled, inpatient isocaloric diet comparison where protein is matched between groups has reported a clinically meaningful fat loss or thermic advantage to the lower-carbohydrate or ketogenic diet.
b) The collective evidence in this vein invalidates the carbohydrate-insulin hypothesis of obesity. However, ketogenic diets have shown appetite suppressing potential exemplified by spontaneous caloric intake reductions in subjects on ketogenic diets without purposeful caloric restriction.
c) Athletic performance is a separate goal with varying demands on carbohydrate availability depending on the nature of the sport. Carbohydrate restriction can have an ergogenic (performance boosting) potential, particularly for endurance sports.
d) Effects of carbohydrate restriction on strength and power warrant further research.
e) Table 2 on page 10 details the different diet types. Below is a summary of the evidence and practical implications:
i) VLED = 800kcal per day liquid formula that has a full range of micro-nutrients. Should be high in protein 70-100g/day.
1) Shown to induce rapid weight loss (1.0-2.5kg per week) in the obese population.
2) The initial rapid weight loss can beneficial for long-term adherence.
3) No more effective than LED over 1 year.
4) To preserve LM and resting metabolic rate, VLED should be accompanied with resistance training.
5) The highest risk of all diet types for side-effects should be medically supervised.
6) The maximum duration of usage under question due to some reported deaths and side-effects in people following in the long-term.
ii) Limited utility in the athletic population.
JP: This approach may be an option for the very overweight and obese. People with diabetes must ensure they do this under medical supervision due to the risk of hypoglycaemia from diabetes treatment.
A good friend of mine is doing a PhD at Kings College London on 800kcal diets for people with Type 2 diabetes who are on insulin. In the first week, most Type 2’s on insulin require at least a 50% reduction in insulin. After three months up to 20% were off insulin completely. He reliably informed me of the absolute necessity of medical supervision, otherwise serious hypoglycemia is a major issue.
This approach would also lead to massive reductions of insulin for people with Type 1. But obviously, they would NEVER come off insulin. Again, medical supervision is a MUST if choosing this as an option.
If choosing this approach, be sure to complement with resistance training, otherwise, you risk losing muscle mass which will hinder your efforts to keep off the body fat off.
This approach would very likely lead to big muscle loss in lean individuals and is not recommended.
PG: Personally I don’t see the point in following a very low-calorie diet unless you are wanting to act a part in a movie.
It’s highly restricted and unsustainable.
Imagine the food cravings
Imagine the fatigue
How would it affect your work life, relationships, never mind sex life?
What will you do the minute the diet ends?
More than likely eat yourself back to where you started.
If you decide to follow this kind of approach (for whatever reason), please ensure you are under medical supervision and have a proper reverse diet/activity regime in place to get you back into a sustainable way of living.
Lean individuals – stay clear!
e) LED = 800-1200kcal based on real food. Smaller portion sizes and based on healthy eating principles.
i) Over 1 year shown to be as effective as VLED, but not as much initial weight loss.
JP: This approach may be an option for the very overweight and obese. People with diabetes must ensure they do this under medical supervision due to the risk of hypoglycemia from diabetes treatment.
This approach would very likely lead to big muscle loss in lean individuals and is not recommended.
PG: Similar to above.
No one wants to live on a diet of ice cubes, lettuce and sweetener.
The more extreme the approach, the more extreme the rebound.
f) Low -Fat Diets (LFD):
i) LFD defined as 20-35% of kcal intake.
ii) VLFD defined as 10-20% of kcal intake – real-life research shows people struggle to keep below 20% of kcal intake from fat. They usually achieve 25% if purposefully lowering fat intake.
iii) If protein levels are adequate, LFD is no better or worse than any other dietary strategy.
JP: I want to dispel the common myth of “Low Fat Diets Do Not Work”. They do work if a consistent energy deficit is achieved. The issue people have with following a LFD consistently is that it does not exclude any food groups.
When a food group is completely excluded, such as carbohydrate in a very low carbohydrate diet, it is very easy to achieve a consistent energy deficit.
Because you have to exclude virtually 70% of all food options. This restriction in choice means fewer decisions, making an energy deficit easy to keep to in the short to medium term.
You can educate yourself on how to be flexible diet with your diet. You’ll have so much freedom and avoid feelings of anxiousness that come with food restriction. Check out The Diabetic’s Guide to Flexible Dieting in the execution guides section.
PG: Fat is the most calorie dense macronutrient known to man.
At 9kcal per gram, removing fat will easily promote a calorie deficit and support fat loss.
However, consuming a low-fat diet can increase the risk of essential fatty acid deficiencies. Therefore, it is essential to supplement with a good quality EPA/DHA fatty acid oil or capsule.
Low-fat diets may be hard to stick to a food choice is massively reduced. This may prove frustrating and unsustainable.
In my opinion, there is no need to avoid an entire food group. We know fat is calorie dense. Its intake simply needs to be regulated within a tightly controlled calorie guideline that is specific to an individual’s goals.
g) Low Carbohydrate Diets (LCD)
i) LCD has many definitions:
1) Less than 40% of energy intake, usually less than 200g
2) Non-ketogenic LCD usually 50-150g
3) Ketogenic diets (KD) less than 50g
ii) There is reasonable evidence of slightly increased weight loss of LCD compared to “standard diet” in overweight people, but only between 0.5 – 1.5kg (1-3lb) over a long period. This is not a large difference in practical terms for the overweight and obese.
iii) In most of the studies, protein intake was not adequately controlled for, which may invalidate the difference found.
iv) All trials that controlled for protein intake did not find any further benefit beyond energy restriction for LCD.
JP: Following a LCD is popular for people with diabetes. LCD will lead to weight loss success if an energy deficit is achieved consistently. As discussed above, this is made easier by this diet type eliminating 70% of available food options.
As dietary carbohydrate content decreases and protein increases, people with type 1 diabetes may require a different insulin doing strategy. Some people count protein grams and use a different insulin dosing algorithm.
People with type 2 diabetes may need to adjust their blood glucose lowering medication such as sulphonylureas and insulin.
PG: Similarly, to low-fat diets, low carb diets remove an entire food group leading to fewer calories consumed and greater rates of fat loss due to a calorie deficit.
Low carb diets are popular in people with diabetes as carbohydrate is the most potent macronutrient for increasing blood glucose levels.
People with diabetes must be prepared to adjust their medication regimen when consuming less carbohydrate.
Low carb diets may be challenging to stick to as carbs are an incredibly tasty food option. If the diet can’t be sustained – it will not be successful.
h) Ketogenic diets (KD)
i) Typical macronutrient breakdown:
1) Less than 50g carbohydrate (10-15% energy intake)
2) Protein 1.2-1.5g per Kg per day (0.5 – 0.8g per pound) (10-25% energy intake).
3) The remaining as fat (60-80% energy intake.
ii) To be in nutritional ketosis the blood ketone level needs to be 0.5-3.0mmol/l with a maximum of 7-8mmol/l.
iii) Metabolic ward studies have proved there is no advantage of a KD vs. LFD, if the protein and energy intake are fixed.
iv) When energy intake is not controlled for there is some evidence that KD may suppress appetite more effectively than “standard weight loss diet”. However, it is not known if this is due to a higher protein intake or having ketones of 0.5-3.0mmol/l.
v) Research into elite athletes shows on the whole that KD is detrimental to performance, epically in those events requiring a high level of ATP production.
vi) The only study showing a benefit was for gymnastic performers, but protein was not controlled for. The KD group consumed 2.9g/kg/d vs. 1.2g/kg/d for the standard diet.
JP: Following a KD is becoming popular for people with diabetes. It can be successful for weight loss because you now have to eliminate 95% of food options. Beware, this risk of micronutrient deficiency is very high unless you eat an extremely well-formulated KD and use micronutrient supplements. I know this very well after following a KD for six months, supplements are needed.
As dietary carbohydrate decreases and dietary fat increases, people with type 1 diabetes may require a different insulin doing strategy. They often require higher background insulin doses with very small bolus doses at meals times. For example, my basal insulin percentage increased from 45% on “normal diet” to 75% on KD.
People with Type 1 diabetes must know the difference between nutritional ketosis and diabetic ketoacidosis (DKA).
It can be a challenge for people with type 1 diabetes to achieve nutritional ketosis because:
Performing the high-intensity work required to build muscle is very challenging when there is a lack of glucose to fuel lifting weights. It is not impossible, but much harder to reach this training intensity when following a KD. For example, my total gym performance reduced by 10-20% on the KD, I did not have the glycolytic fuel to power higher volume sessions at high intensities.
Often people think they are in nutritional ketosis because they are “following the diet”. In reality, their ketone levels are rarely above 0.6mmol/l. If you are going to follow the KD, be sure to test your blood ketone levels regularly to ensure they are 0.5-3.0mmol/l.
People with type 2 diabetes may need to adjust their blood glucose lowering medication such sulphonylureas and insulin.
PG: Keto has become fashionable in the world of health and fitness.
It certainly works.
Limiting carbohydrate reduces calorie intake and helps promote a calorie deficit. While prioritizing fat and protein increases satiety leading to fewer calories consumed and greater levels of fat loss.
However, keto diets are highly impractical for most people with diabetes who lift.
It takes a dedicated period of carbohydrate restriction and low insulin levels to enter dietary ketosis.
If you’re using injectable insulin and accidentally take too much – you run the risk of delaying this process when treating a hypo with carbohydrate.
Bringing you back to square one…
If your blood glucose goes high and needs to be corrected with a larger than normal amount of insulin – you potentially delay the process.
Weight training relies exclusively on carbohydrates for fuel.
Ketogenic diets restrict carbs – jeopardizing the training stimulus.
Plus, the idea of going low carb is mental masochism for most, especially when eating out.
Then again if you love protein and fat rich foods over carbs, have rock solid glucose control and feel your performance is OK on lower carbs –go for it.
i) High-Protein diets (HPD). Increasing dietary protein to levels significantly beyond current recommendations for athletic populations may improve body composition.
i) The ISSN’s original 2007 position stand on protein intake (1.4–0 g/kg) has gained further support from subsequent investigations arriving at similar requirements in athletic populations.
ii) Higher protein intakes (2.3–1 g/kg FFM) may be required to maximize muscle retention in lean, resistance-trained subjects in hypocaloric conditions.
iii) Emerging research on very high protein intakes (>3 g/kg) has demonstrated that the known thermic, satiating, and LM-preserving effects of dietary protein might be amplified in resistance-training subjects.
iv) It is possible that protein-targeted caloric surpluses in outpatient settings have resulted in eucaloric balance via satiety-mediated decreases in total calories, increased heat dissipation, and/or LM gain with concurrent FM loss.
v) Protein pacing over 4-6 meals per day is superior to lower frequency of intake in hypocaloric conditions.
JP: The two big questions are:
As dietary carbohydrate decreases and dietary protein increases, people with type 1 diabetes may require a different insulin doing strategy. It may be required to count protein and use a different insulin dosing algorithm.
PG: I personally consume a minimum of 1.6g Protein P/Kg bodyweight daily. This is my benchmark.
When it comes to fat loss I purposely increase my protein intake to the higher ends (2.0-3.0g/kg) to assist with appetite control. Protein also costs more energy to digest than fat or carbohydrate.
So, we have a nutrient that fills us up (reducing calorie intake overall) and doesn’t yield its 4 kcals per gram – because it costs a lot of energy to digest.
When it comes to mass gain I consume the lower end of the scale for protein. 1.6-2.0 g/kg. Eating too much protein will hinder my appetite – this is a problem when a calorie surplus is the goal.
6. Intermittent Fasting (IF). Time-restricted feeding (a variant of IF) combined with resistance training is an emerging area of research that has thus far shown mixed results. However, the body of intermittent caloric restriction research, on the whole, has indicated no significant advantage over daily caloric restriction for improving body composition.
a) Therefore, programming of linear versus nonlinear caloric deficits should be determined by individual preference, tolerance, and athletic goals.
b) Adequate protein, resistance training, and an appropriate rate of weight loss should be the primary focus for achieving the objective of LM retention (or gain) during FM loss.
vi) The different types of IF:
1) Alternate Day Fasting (AFD):
a) 24hours fast, followed by 24-hour feeding window
b) Compensation on feeding day does not equate to energy deficit achieved on the fasting day.
c) Over 6 months a slight increase in weight loss compared to daily kcal restriction.
2) Whole Day Fasting (WDF)
a) Two 24 hour fasts in a week
b) One trial showed greater weight loss for WDF vs. a daily energy restriction (DER). This was due to the compliance of WDF (70%) vs. DER (38%).
3) Time Restricted Fasting (TRF)
a) Fasting periods of 16-20hrs and feeding periods of 4-8hours
i) One well-controlled study on resistance trained people where protein intake was adequate a 1.8-1.9g/kg showed an improvement in LM and FFM for a 16 hour fast/8hour feed vs. usual intake when all dietary variables were controlled for. The proposed benefit is thought to be due to increased Adiponectin. It should be noted that testosterone was lower in the fasting group. Future studies are awaited to corroborate this finding.
JP: IF can potentially be of extra benefit for people with diabetes for one important reason:
PG: I am a massive fan of IF for a number of reasons.
There are plenty of positives of IF that make eating enjoyable and help improve adherence.
On the flip side there a few downsides or implications of IF.
7. The long-term success of the diet depends upon how effectively the mitigating factors of the homeostatic drive are suppressed or circumvented. Hypocaloric conditions for fat loss have resulted in adaptive thermogenesis – a larger than predicted decrease in energy expenditure (10–15% below the predicted drop in Total Daily Energy Expenditure (TDEE) after accounting for LM and FM loss.
a) For continued fat loss the Calories in Calories Out (CICO) balance need to be in a negative balance.
i) The Calories in is easy to quantify by weighing food and using food labels. Although the difference from labels to actual food can be up to 25%.
ii) The Calories Out often termed Total Daily Energy Expenditure (TDEE) is much more variable due to:
1) Basal Metabolic Rate (BMR). The calories burned at complete rest. This usually accounts for 60-70% of TDEE. If you have high muscle mass do you get a massively increased BMR?
a) NO! It is the heart, brain, liver and kidneys that make up 70-80% of BMR.
b) Increase muscle will increase BMR but not to the extent most people believe.
2)Thermic effect of food (TEF). This accounts for 8-15% of TDEE. Ways to increase this:
a) Protein is the most energy demanding. Higher protein diets have a higher TEF.
b) Whole foods require more processing and have a higher TEF.
3) Non-Exercise Activity thermogenesis NEAT is the energy expenditure of occupation, leisure, basic activities of daily living, and unconscious/spontaneous activity such as fidgeting. It ranges from 15% of TDEE for the sedentary to 50% in people with a very active job and lifestyle.
4) Exercise Activity Thermogenesis (EAT), the purposeful activity such as gym sessions, HITT, and cycling. This accounts for 15-30% of TDEE depending on the planned activities of individuals.
JP: Simple strategies to keep TDEE high will be:
PG: In order to keep TDEE high try the following.
8. Adaptive Thermogenesis is where the body reduces Calories Out when weight lost. Typically, when more than 10% of body weight is lost, the TDEE drops by 20-25%!
However, the majority of the existing research showing Adaptive Thermogenesis has involved diets that combine aggressive caloric restriction with low protein intakes and an absence of resistance training; therefore, essentially creating a perfect storm for the slowing of metabolism. Research that has mindfully included resistance training and adequate protein has circumvented the problem of Adaptive Thermogenesis and lean muscle loss, despite very low-calorie intakes.
JP: When aiming to lose 10% or more of body fat two things are essential:
PG: In order to keep TDEE high, follow the similar steps outlined in the point 7.
Each activity mentioned will help you burn more calories across the day.
A few things are absolutely clear:
“Fat loss is driven by a sustained caloric (energy) deficit.”
A few special considerations for people with diabetes:
One final point to consider is how well you follow a plan, and how you respond to expectations?
But when someone else is holding you accountable to meeting deadlines or following a plan, you smash it! If so you need someone who you trust to hold you accountable to your plan: