The next in our insight series on building an effective fat loss phase revolves around the role of nutrient timing. In each of the previous insights, we’ve looked at what cornerstones need to be in place for a successful outcome to occur. We’ve looked at factors such as upper and lower limits for rates of loss through to the role of macronutrients and activity balance, whilst providing practical guidelines along the way for individualised success.
If this is your read of an insight in this series, it may be worth looking back through those mentioned to give some context to todays post (1,2,3,4,5). To begin this weeks insight, we first need a quick review of the equation we’re trying to control, the balance between fractional synthetic rate (FSR) and the fractional breakdown rate (FBR) of fat and muscle tissue. How much we maintain vs how much we breakdown and utilise for fuel. As we know, our primary goal is for the FBR to be greater than the FSR in relation to fat tissue (lose more than we store), whilst ensuring the FSR is greater than the FBR for muscle tissue to ensure maintenance of muscle mass (maintain more than we lose).
Alongside the recommendations for calorie and macronutrient consumption, the role of FSR and FBR for both fat and muscle tissue can give us a firm starting point on understanding nutrient timing for fat loss.
Our first consideration is time spent with muscle fractional breakdown rate elevated. Fundamentally we DO NOT want this to occur. FBR elevation in muscle tissue is us losing muscle mass over time. Whilst the body has its own naturally occurring cycles of FBR/FSR, we do have some control over preventing FBR elevations in muscle tissue something we are actively trying to prevent.
Equally, any time that FSR of muscle tissue is elevated, but we aren’t providing the body with the resources it needs is likely to be an inefficient use of nutrient timing. We want the body to have the resources (amino acids) readily available within our system when FSR is elevated.
The result of the balancing act between these first two variables is to target a roughly even spread of meals across the day within reason. This provides the nutrients required when FSR of muscle tissue is elevated, whilst ensuring alternate forms of energy are available (eg. carbohydrates) to prevent the use of muscle as a fuel source. Assuming a regular 7-9hr sleep cycle for each of us, this leaves approximately a 14-16 hour eating window within the day for food consumption.
Ghrelin, one of the key hunger regulating hormones, increases within the stomach during periods without food. These levels peak in a cycle approximately every 4 hours, triggering the feelings of hunger and the need to search out food. If we use this 4 hour window as an indicator for FBR elevation occurring, we can break the 16 available hours into 4 hour windows. This creates a potential minimum of 4 meals per day within these limits. At our lower limit, anything below this number is likely to create periods in which the FBR and hunger levels are unnecessarily elevated.
Our higher limit on the number of meals is likely to be impacted by the total overall calories available for an individual. For example, a person consuming 1800kcal under the hypocaloric conditions needed for fat loss, over 4 meals will consume approximately 450 kcals per meal. A manageable amount that can contain adequate amounts of protein, carbohydrates and fats.
If we extend this 1800kcal target out to 6 meals per day and our individual is consuming approximately 300kcals per meal, now depending on food choices and composition (high calorie density, low volume vs high volume, low calorie density) this could simply be a very small amount of food to actually take in each meal with little overall added value or we may miss out on reaching sufficient macronutrient intake per meal.
Alternatively however, an individual needing to take in 2800kcal still within the same rate of loss as our 1800kcal individual, would be consuming 700kcal per meal based on 4 set meals per day. Depending on food composition again, this could be some very large volumes of food that may be unmanageable to adhere too in the longer term.
In these circumstances, this individual may actually benefit from stretching out to 5-6 meals per day, as it would not only create a more sustainable balance (470-540kcal), but would also prevent further any periods in which muscle FBR could be elevated, or muscle FSR is elevated but the needed resources aren’t present.
Above 7+ meals per day however is likely to either dilute the food volume and calorie density to a point in which meals don’t provide adequate satiation, or alternatively create a barrier to continued adherence purely by the need to eat at such regular intervals (2 hours) when in a hypocaloric phase. Interestingly, under hypercaloric weight-gaining phases, these higher meal frequencies may actually be advantageous when calorie intakes are much higher.
However our general recommendation would therefore be to have a roughly even spread of meals across 4-6 set points within the day depending on total calorie intake.
As a brief side-note, this does bring into mind the potentially controversial role of shortened windows of food consumption in the form of fasting and its’ many types. Hopefully, based on the factors we’ve outlined within our insights so far in this series, we can potentially see where some of the pitfalls of these types of strategies may occur. Whether it be a daily fasting window (16hr fast, 8hr food window), alternate day, or variations on the theme such as a 5:2 approach (5 days regular eating, 2 days very low calorie allowance), research seems to indicate that they CAN be effective in terms of promoting weight loss if a calorie deficit is maintained. The caveat here however is the term weight loss…
As we have underlined within this series, muscle mass maintenance is fundamental to effective body composition changes long term (1).
Our goal is not to simply to become an overall smaller version of ourselves, but to lose what we would consider non-essential tissue, i.e excess body fat levels. In approaches that involve intermittent or modified fasting regimes with very low calorie allowances, we are increasingly likely to see elevated rates of muscle mass loss in the absence of any/and or alternate forms of energy supply. We are also likely to run head-first into many of the psychological barriers that we are directly trying to avoid in creating effective long term strategies for weight loss, which our first insight outlined (1).
Jumping back to our nutrient timing basics. Not only are we looking for a roughly even spread of meals across the day, but we can also preferentially manipulate the intake of certain macronutrients to assist in longer term maintenance and effectiveness of fat loss phases and offset some of the downsides and tradeoffs associated with being hypocaloric for extended periods of time.
Due to the role of protein within the FSR of muscle mass, a similar spread roughly even across the day is likely to provide benefit. As we broke down in our previous article on the purpose of macronutrients and recommendations, consuming approximately 25g of protein in itself is likely to be sufficient to stimulate the muscle protein synthesis (building) response within the body. Using this as our guide, an even split of protein aiming for upwards of 25g per meal is likely a good starting point.
This of course can be scaled across the day to match the typical intake and preferences of individuals for protein. For example, a individual weighing 150lbs aiming to take in 1g/lbs of protein for a daily total of 150g, could have 5 meals per day with the following breakdown.
- Breakfast – 25g
- Post Training Whey Protein Shake – 25g
- Lunch – 30g
- Snack – 25g
- Dinner – 50g
In this example, we’ve hit the minimum requirements across all meals (25g) but used the remaining intake around both lunch and dinner to allow for larger meals and intake at these times.
When it comes to carbohydrate intake, performance considerations need to be made. In the case of an individual who’s training performance is a key factor, it may benefit to increase carbohydrate intake prior to a workout that has either high intensity or long duration to provide the necessary fuel for high-level activity. This may also benefit individuals who struggle either physically or psychologically with having to train in a state of hunger. If performance, duration or hunger is NOT a factor, carbohydrates can be spread evenly in a manner similar to protein.
Some consideration should also be made to the composition of the carbohydrate and protein sources. Fruits and vegetables, whilst low in overall calorie density, are high in food volume, water and fibre content. Consuming a meal prior to training that is high in total volume of these food types, whilst limited in the calorie total, may provide additional gastrointestinal distress purely from the amount of food, water content and fibre intake. It may benefit therefore for pre-workout carbohydrates to be from simple or liquid forms to provide fast acting fuel sources as well as limiting potential gastrointestinal discomfort. Likewise, consuming a lean protein source in the hours leading up to a training session may be uncomfortable for some, whilst a liquid form (eg. whey protein shake) may be a more reliable approach.
In the post-workout window, in which the muscles are primed for re-uptake of nutrients, there may be benefit in having higher carbohydrate consumption alongside protein intake due to the glycogen and insulin-mediated benefits associated with carbohydrates.
Fat intake is likely to the dependent upon the individual and the amount consumed. Under traditional hypocaloric conditions, the overall amount of fat is likely to be low (0.3-0.4g/lbs). Therefore this isn’t of too much overall concern outside of the total daily intake. However around training and performance, it may be beneficial to skew fat intake away from training due to the slower rate of digestion that takes place with these macronutrients, especially in individuals in which an individuals bodyweight means the absolute values may be higher (eg. 220lbs taking on 0.4g is 88g of Fat).
Taking all recommendations and considerations into account, we can create a simple client example to detail how this may look.
- 2500kcal target
- ~216g Protein (1.2g/lbs = 864kcal)
- ~54g Fat (0.3g/lbs = 486kcal)
- ~287g Carbs (remaining kcal = 1150kcal)
Breakfast: (370kcal total)
- 30g Protein (120kcal)
- 10g Fat (90kcal)
- 40g Carbs (160kcal)
Pre-Workout: (200kcal total)
- 25g Protein (100kcal)
- 25g Carbs (100kcal)
Lunch/Post Workout Meal: (615kcal total)
- 50g Protein (200kcal)
- 15g Fat (135kcal)
- 70g Carbs (280kcal)
Snack: (285kcal total)
- 30g Protein (120kcal)
- 5g Fat (45kcal)
- 30g Carbs (120kcal)
Dinner: (780kcal total)
- 60g Protein (240kcal)
- 20g Fat (180kcal)
- 90g Carbs (360kcal)
Snack: (265kcal total)
- 25g Protein (100kcal)
- 5g Fat (45kcal)
- 30g Carbs (120kcal)
In this example we preferentially bias higher total calories around traditional meal times (breakfast, lunch, dinner) whilst also considering lower fat intake prior to training, higher carbohydrate intake in the post-workout window as well as ensuring regular protein feedings of >25g.
A non-training day may potentially see a more even spread of macronutrients, a drop to 4-5 meals and condensing of calories to accommodate, or an alternate distribution of calories to suit the individual needs.
This is just one example of overall nutrient timing basics and macronutrient manipulation. However in spite of the value that may benefit individuals in understanding these factors, the singular target always needs to be in making sure the process is both sustainable and manageable over the long term.
Having too rigid a a structure with nutrient timing often leads to additional psychological stress due to the impracticality of life in making sure every target is hit at every window every single time. However, remember to prioritise based on the fundamentals will keep progress in check.
Overall calorie balance and maintaining a hypocaloric state is far more important than the daily distribution.
Getting in the overall total level of protein per day, is more important than getting exactly 4-6x servings of 25g.
Aiming for a roughly even spread of meals across the day, without excessive windows of hunger, is more important than the potential additional stress of eating on the clock every 3-4 hours regardless of where you are and what you’re doing.
As with all recommendations we’ve made so far in this series, upper and lower limits do exist. Staying within these windows as often as possible is the key for long term outcomes. Having a structure that allows some degree of flexibility within these ranges that takes into account that natural challenges that daily living provides is the foundation of a success body composition change.
In our next insight, we will begin to look at how to maintain progress once a body composition phase has began. What to track, how to adjust calories dependent on rates of weight loss and what macronutrients to adjust to create successful outcomes.