We have seen that whenever anything is changed in the diet, increasing or decreasing calories or changing the proportion of various macronutrients within the body, many opposing forces are activated. At this point one might perhaps perceive some confusion as to which macronutrients should be given priority, i.e. what the correct proportion of the three substances in the diet should be. In principle, a high-carbohydrate diet has more anabolic than catabolic effects, i.e. it is more conducive to an increase in tissue, lean and fat, than to its loss. On the other hand, even if the goal is weight loss, completely eliminating carbohydrates from the diet is not possible, not only as a matter of optimising fitness, but also because, as already mentioned elsewhere, there are certain organs in the human body that feed preferentially on carbohydrates. And even eliminating them almost completely is not an optimal solution, because, considering the influence of insulin on leptin, the metabolism would drop very early, bringing the slimming process to a halt. This does not detract from the principle that a low-carbohydrate diet, while avoiding any excess, is more effective in slimming than a high-carbohydrate diet. When it comes to recovery, on the other hand, a high-carbohydrate diet, combined with higher average insulinemia, is better than a low-carb diet. The protein content, on the other hand, should be the higher the strength- and power-oriented efforts in the context of training. If, then, one wishes to increase muscle mass, then the amount of protein to be introduced in the diet should be even higher. Be clear, however, that protein will not increase muscle mass. What will lead to an increase in it is the training geared towards it. The high-protein diet is only a premise.

Calorie quality for weight loss

  A prerequisite for a weight-loss diet to work is a relatively high level of leptin in the bloodstream. In terms of nutrition, this almost always translates into a high-carbohydrate diet. Conversely, however, a high-carbohydrate diet, as already seen, due to the influence of carbohydrates on insulin, is unlikely to lead to weight loss. This apparent paradox can be resolved by distinguishing between two different diet periods:

1. a high-carb (high-carbohydrate) phase, in which the preconditions for slimming are built up, although it is not immediately geared to this purpose;
2. a low-carb phase, in which the fruits of the previous work on leptin are reaped, trying to reduce insulin levels.

It should be made clear that the blood levels of leptin at the end of the high-carb phase will only remain compatible with a slimming regime for a limited period of time, after which the slimming in the low-carb phase will stop. The diet will therefore necessarily have to assume a cyclic structure. With regard to the results to be expected, since the introduction of carbohydrates into the diet must by necessity be gradual (on pain of an out-of-control increase in body weight), the high-carb phase will have to be longer the lower the average daily carbohydrate intake of the original diet. An average Italian, accustomed to consuming copious amounts of flour and various baked goods (e.g. pasta or bread) and an average amount of legumes, could even do without the first phase. If, on the other hand, one comes from a low-carb diet experience (perhaps a long and very drastic one), then one will have to prepare oneself psychologically for a long preliminary phase (even one year). The weight loss of the second phase, on the other hand, will be all the greater the longer and more carbohydrate-rich the diet of the preliminary phase was, and the further away from peak fitness one is with regard to body composition. More specifically, with regard to this last point, a very overweight individual will lose weight faster than one who is already fairly thin.

The high-carb phase: metabolic restoration

  The high-carb phase is geared towards increasing average blood levels of insulin so that this hormone can stimulate significant leptin production. As we have seen, in fact, a fair amount of leptin in the bloodstream is a prerequisite for the success of a weight-loss diet programme. We have also already mentioned what this phase consists of: it is, trivially, a matter of increasing the amount of carbohydrates in proportion with the other two macronutrients as much as possible without this resulting in out-of-control fat accumulation. This is possible when the carbohydrate increase is in the range of a few grams per day per week. By avoiding abrupt variations, in fact, it should be possible to accustom the body’s metabolic rate to increase just enough to compensate for the insulin-induced increase in anabolism. The high-carb phase, however, however unavoidable, exposes you to several dangers. The first of these, as already mentioned, is the out-of-control accumulation of fat mass due to increased insulinemia. During this phase, it is actually normal to gain some weight. The important thing is that the fat accumulation is controlled. The criteria for determining whether fat accumulation is acceptable or not are the same as those seen in the part on setting the calorie quantity for building up the metabolism. Other dangers are always related to insulinemia: having to consume a significant amount of carbohydrates, in the absence of certain precautions, the endocrine pancreas may produce more insulin than is actually needed to keep blood sugar under control. This will lead, on the one hand, to crises in energy availability during athletic exertion and, on the other hand, to loss of muscle mass due to activation of the gluconeogenetic process. In order to prevent reactive hypoglycaemia, it is important that the introduction of glucose into the blood stream is as gradual as possible (with exceptions to be discussed below). One way to prevent abrupt changes in blood glucose is to monitor a particular parameter of the diet: the glycaemic load. Quite simply, the glycaemic load is the product of the glycaemic index of a food by the amount of carbohydrates contained in the food consumed, divided by 100. It can be extended to an entire meal by adding up the glycaemic load of all the foods consumed. Well, the lower the glycaemic load of the meal, the more the blood glucose will be under control and the fewer the side effects associated with an inconsistent blood glucose level. The third danger inherent in the high-carb phase is related to insulin resistance. We have already seen what the problems with insulin resistance are, so it should be sufficiently clear that it is a condition, due to a massive intake of dietary glucose, that should be avoided at all costs. Not only because, as mentioned, it is the antechamber to senile diabetes, but also because it leads to an out-of-control accumulation of body fat and because it impairs the post-training recovery process. With regard to the latter point, in fact, it is insulin that is the main messenger signalling the peripheral cells to replenish themselves from the blood with all the nutrients and plastic substances to be replenished after training. Cells that are unresponsive to insulin tend to recover from exertion in a sub-optimal manner. Now, we have seen that insulin, when the carbohydrate intake is not very high, remains within the normal range, also due to the self-regulating action exerted on lipo-protein-lipases. Well, to ensure that the glucose intake reached is not such as to generate insulin resistance, it is possible to check fasting blood glucose levels with a small, inexpensive accessory called a glucometer, sold in pharmacies and parapharmacies, as well as on the Internet. The glucometer has a small needle with which you have to prick your finger. The device will measure the amount of glucose in your blood (usually milligrams of glucose per decilitre of blood). Values above 100mg/dl on an empty stomach are considered an indication of insulin resistance and a sign that the glucose accumulation phase needs to be interrupted. Let us conclude the section on metabolic restoration with a couple of suggestions: since the aim is to shift the diet in a hyperglucidic direction, this may require compensatory intervention in protein and, above all, fat, so as to keep the calorie intake balanced. In practice: if carbohydrates are increased, it may be necessary to reduce protein and fat in order not to vary (out of control) the calorie intake. Finally, we have seen that body weight, during the metabolic recovery phase, tends to fluctuate around an average value. Well, to prevent excessive weight gain, one could choose to increase carbohydrates, instead of every week, only in those weeks when the weight is reduced.

The low-carb phase: establishing catabolism

  During this phase, as already mentioned, the aim is to finally reap the rewards sown during metabolic restoration. Since in order to do this it is necessary to establish the catabolic state, and since this state is incompatible with high levels of insulinemia, a drastic cut in carbohydrates in the diet is made in order to lower the latter. The influence of carbohydrate cutting on insulinemia, however, is not only a direct consequence of lower blood glucose, but also of the reduction of insulin resistance: low carbohydrate intake often means a depletion of muscle and liver glycogen stores. And since insulin resistance stems, in large part, from an excessive influx of glucose to the peripheral cells, it goes without saying that reducing glycogen stores will make them more responsive to insulin and, more generally, to the stresses aimed at their trophism (with significant benefits for recovery processes too). This will therefore imply less need for insulin secretion by the endocrine pancreas to effectively regulate glycaemia. Returning to carbohydrate cutting, ideally, one should reduce carbohydrates as much as possible without this resulting in post-workout recovery problems. In fact, as we have already seen, insulin and the anabolic state it is responsible for are essential for optimal recovery from training efforts. In a situation of low insulinemia, the peripheral cells are not in fact oriented to take nutrients and plastic material they need from the blood stream to replenish the losses incurred during the application of the training load. It is therefore necessary to identify that threshold of average daily glucose intake below which it is not possible to fall without damaging performance. This threshold is called the glucose (or carbohydrate) set point. To find it, I suggest (to the average committed athlete) starting with an average intake of 100g/day and then increasing or decreasing it depending on the body’s reaction in terms of the effectiveness of the recovery process. More specifically, if one does not notice any problems with recovery and, more generally, training performance is not affected by the carbohydrate cut, then one can consider reducing carbohydrates further by 10-20g/day. If, on the contrary, you notice a general difficulty in recovering from training fatigue, then you will necessarily have to increase the amount of this nutrient. One proceeds in this way, continuing to decrease or increase carbohydrates, until one finds the minimum threshold of carbohydrates that one can take in daily (on average) without running into problems with the quality of post-training recovery. Some athletes (as well as sedentary people) can afford very drastic carbohydrate cuts (taking only 30-50g/day), which have an additional benefit for those wishing to lose weight: the establishment of a state of ketosis (not to be confused with keto-acidosis). Now, before delving into the subject of ketosis, a brief premise is in order: the human body is able to adapt to the macronutrients it is predominantly supplied with in order to derive the energy it needs to survive. This implies that if one follows a predominantly carbohydrate diet, the body will favour carbohydrates as an energy source. Conversely, if one follows a low-carbohydrate diet, the body will prefer fats. If, therefore, one consumes a lot of carbohydrates, the body will always use those to produce energy. And if, at some point, it runs out of calories, rather than burning fat, it will prefer to catabolise (i.e. ‘dismantle’) the muscles to take the proteins from them, send them to the liver and transform them into glucose (gluconeogenesis). This, on the one hand, will lead to a loss of muscle mass and, on the other hand, will not make you lose weight, because the storage fat will not be affected. On the contrary, a diet rich in fat and low in carbohydrates will encourage the body to favour fat as an energy source. There is a maxim that says ‘if you want to burn fat, you have to eat fat’. Well, ketosis is the state in which the body becomes accustomed to consuming, instead of glucose, a fuel of lipid origin: ketone bodies or, more simply, ketones. The synthesis of ketone bodies is all the greater the more pronounced and prolonged the glucose depletion undergone. It is possible to measure the amount of ketone bodies in the blood with a special instrument, the ketone counter, whose operation is similar to that of the glucometer: you have to prick your finger with a needle and let a small drop of your blood flow onto a test strip supplied with the instrument and connected to it. The display of the accessory will return the value of ketones present in the blood. As far as reference values are concerned, an amount of ketones below 0.5 mmol/l blood is not considered ketosis; between 0.5 and 1.5 mmol/l blood is considered mild ketosis, while between 1.5 and 3 mmol is optimal ketosis. Higher values, while not providing any more fitness benefits than can be achieved with optimal ketosis, are not compatible with good health. Regarding the time required to establish ketosis, it takes a few weeks for it to take place. More in detail:

1. after about a day of almost complete abstention from carbohydrates (max. 30-50g per day), the glycogen reserves in the liver begin to shrink;
2. In the next three days or so of the hypoglucidic diet, the body is still highly dependent on sugars. Therefore, through gluconeogenesis, it will try to produce them from amino acids derived from protein. In order to prevent, therefore, the proteins catabolised by it to take amino acids from muscle, it is good to keep the dietary protein intake high;
3. over the next three weeks, the body gradually gets used to doing without glucose, so that, at the end of this period, only 25% of the energy it needs will be obtained from glucose, the remaining 75% being taken from ketone bodies;
4. Eventually the body gradually adapts to do without ketone bodies as well, using almost exclusively fats as an energy source as long as the low-carbohydrate diet is in place.

As for the foods to be consumed in order to establish ketosis, since they must, for the most part, be low in carbohydrates (such as meat) or, alternatively, low in calories (such as lettuce), they can be selected from the following:

1. calf;
2. beef;
3. lean cuts of pork;
4. horse;
5. all seafood (molluscs and crustaceans);
6. all birds (except goose and duck);
7. white meat;
8. egg whites;
9. light dairy products;
10. coffee and tea (in moderation);
11. vinegar (in moderation);
12. spices and herbs;
13. homemade lemon juice (in moderation);
14. vegetables;
15. seeds and nuts in moderate quantities;
16. dried fruit in moderate quantities;
17. red meat (in moderation);
18. all fish;
19. egg yolks;
20. cold cuts (in moderation);
21. fatty dairy products (in moderation).

It should be made clear that these foods should be understood as mere suggestions: any food may be included in the diet, as long as the daily carbohydrate intake established a priori during the glucose set point phase is not exceeded. It goes without saying that such a drastic period of carbohydrate depletion will bring with it unavoidable unpleasant effects on basal metabolic energy consumption: insulinemia will always be very low, so leptin and thyroid hormone levels will also be so low that calorie expenditure will drop. In order to prevent premature halting of the slimming process, it may be useful to insert glucose reloading days from time to time, starting at the end of the aforementioned adaptation period. Di Pasquale suggests two days of reloading for every five. However, of course, if the refill days end up being too frequent the state of ketosis would be compromised, so caution is advised. Particularly important is the warning to keep lipid consumption relatively low during the carbohydrate reload phase (I suggest 20-25% of total calories at most). The reason is that the insulin activity implied by high carbohydrate intake will be responsible for the establishment of a new, brief anabolic state. And since this state will mainly involve the storage of nutrients that are largely present in the blood (i.e. those taken in with carbohydrates), it is a good idea to avoid these being lipids. If this were the case, in fact, it would lead to a new weight gain in the adipose (fat) tissue. As for low-fat and low-carbohydrate foods, they are certainly permissible, but it is a good idea to try to satiate one’s appetite with carbohydrate-rich foods in order to counteract an excessive drop in blood levels of leptin and thyroid hormones. A significant benefit of the state of ketosis is that, if it has been established, there is no longer any reason to fear reactive hypoglycaemia. In fact, the body will not activate gluconeogenesis (except, perhaps, to a minimal extent) to raise blood glucose and thus keep glucose available for the cells. This is because the latter will be nourished predominantly by fats. During the glucose-replenishment phases in the context of a ketogenic diet, the indications given above regarding the index and glycaemic load of foods can be disregarded. This benefit does not only affect the practical aspect of producing the diet (which is facilitated) or aspects of meal enjoyment, but also the nutritional quality. Being able, in fact, to freely include in the diet even foods with a high glycaemic index, the diet will be more varied and richer in micronutrients, with certain health benefits. Finally, with regard to the foods to select for the carbohydrate-replenishment phase, you can draw from the following list:

1. calf;
2. beef;
3. lean cuts of pork;
4. lean ham (cooked and raw);
5. horse;
6. skinny fish;
7. all seafood (molluscs and crustaceans);
8. all birds (except goose and duck) without skin;
9. white meat;
10. egg whites;
11. light dairy products;
12. coffee and tea (in moderation);
13. vinegar (in moderation);
14. spices and herbs;
15. homemade lemon juice;
16. salt (in moderation);
17. vegetables;
18. low-fat fruit;
19. pasta;
20. all cereals (rice, maize, barley, oats, rye, etc.);
21. low-fat flour (e.g. bread);
22. all pulses (lentils, chickpeas, chickling peas, lupins, broad beans, etc.).

Now, among the foods listed above (which, like those relating to the carbohydrate depletion phase, should only be understood as suggestions) are foods both rich in carbohydrates and poor in that nutrient (as well as fat). The latter, in fact, as we have seen, are allowed in this dietary context. The foods that should be given priority, however, are the last five on the list, as they are the most carbohydrate-rich.

Caloric quality for weight gain

  Weight gain, as we have already seen, requires a relatively high average insulin level. It is in fact insulin, as the anabolic hormone par excellence, that is mainly responsible for body weight gain. In contrast to what should be done during the carbohydrate-cutting phase for weight loss, here, therefore, carbohydrate intake should be increased as much as possible, but always avoiding exceeding the threshold beyond which insulin resistance levels rise to such an extent as to damage the quality of recovery. If you want to keep body fat mass down, then it is essential to ensure that carbohydrate intake is not such as to encourage an outsized accumulation of it, regardless of aspects of recovery and the supply of new muscle tissue. In order to identify the quantity of carbohydrates to be taken as a percentage of the other two macronutrients, gradualness is essential. Two different phases are therefore identified:

1. the search for optimal carbohydrate intake as a percentage of the other two macronutrients;
2. the hyperglucidic diet with the percentage carbohydrate intake identified above.

The optimal carbohydrate intake

The search for the optimum carbohydrate intake follows the same criterion as the gradual increase seen in the section on high-carb diets for metabolic restoration, the only difference being that here one should continue to increase the carbohydrate intake until there is an improvement in body composition in terms of weight gain. In other words, as long as muscle mass increases in the right proportion in relation to fat mass, one can continue to increase the carbohydrate intake. As soon as an excessive accumulation of fat in relation to muscle mass is detected, this phase should be discontinued. For the more daring, it is possible to consider a somewhat less gradual increase in percentage glucose intake than would normally be observed in metabolic restoration diets.

The hyperglucidic diet

  Once the optimal amount of carbohydrate intake has been identified, the phase of progressive carbohydrate increase can be stopped and the diet stabilised at the identified level. This phase can be continued as long as the body weight can be increased by changing the body composition in the desired manner. It must be made clear that the positive influence of the diet on body composition will in any case have a limited duration, both due to factors inherent to training (as one improves, it is easier to run into stalls and various performance problems), and due to aspects related to hormonal activity (particularly insulin resistance). If you don’t want to encounter immoderate accumulations of fat and problems with recovery, it is therefore a good idea not to force the continuation of this phase when you encounter difficulties in continuing to improve your body composition or recovering well from training fatigue. At the end of this phase, if you are interested in disposing of body fat, you can introduce the low-carb diet for weight loss; otherwise, you can return to the initial maintenance diet for a few weeks.