Fructose has recently received considerable attention as one of the factors behind the growing obesity problem, particularly in the USA. Fructose contribution to obesity can be traced mainly to soft drinks sweetened with fructose syrup. Because soda consumption has increased alarmingly and therefore energy intake, while physical activity is reduced so maybe not the fructose can be viewed as a single villain of the piece.
Fructose is metabolized differently than glucose and therefore has little other impact on the body. Fructose absorption in the intestine is done not by the same transport mechanism as glucose, which in and of itself does not affect the uptake rate significantly, but uptake is independent of sodium, in contrast to glucose. Therefore, it can increase carbohydrate uptake and glucose use during strenuous fitness sport with 20-55% by simultaneously adding fructose to glucose, glucose polymers, or even in combination with sucrose.
However, what may cause problems at high fructose intake is that fructose does not have the same biochemical degradation in the liver as glucose. You could say that fructose enters further down the chain of glucose and glycogen breakdown structure and jump because of some processes that normally regulate the formation and breakdown of glucose. The energy from fructose will be entered into the system relatively unregulated, so that in comparison to glucose, several times easier to form fat from carbohydrates. Since there is glucose influx and decomposition of glucose that stimulates insulin production in the pancreas, which the fructose part is passing, so fructose stimulates insulin secretion is not the same as glucose. Insulin answer is several times lower as fructose must be converted to glucose before it stimulates insulin production. Blood glucose is increased very slowly after ingestion of fructose because it must be converted to glucose first before it becomes "blood sugar". Fructose is a "slow" carbohydrate source with a low glycemic index.
One of insulin's effects is to slow the breakdown of fat cells, because when it is available carbohydrates (and thereby increasing insulin levels) as the glucose used as a primary energy source. When fat digestion decreases, levels of free fatty acids in the blood and because the uptake of fatty acids is directly proportional to levels outside the cells, which also reduces fat transport into the cell and thus fat burning.
The effects of a moderate intake of fructose is therefore a slower rise in blood sugar after meals and less inhibition of fat metabolism. This is good and you have seen that fructose in the diet, about 50-100g or 10-15E%, in type 2 diabetics produce smoother and lower blood sugar levels without affecting blood lipids negatively [3, 5, 8-11]. Fructose can also improve glucose tolerance in those with impaired glucose tolerance by acting catalytically on glucose metabolism in the liver. A subsidy of about 10% of the amount of carbohydrate from fructose lowers blood glucose and insulin response after glucose load even though the amount of carbohydrate in total is greater.
Problems arise when the amount of fructose is high and especially in the context of an energy surplus. Because fructose does not slow the breakdown of fat and rather stimulates fat formation in the liver, so this implies dyslipidemia and insulin resistance (mainly in liver and adipose tissue). This has been clearly demonstrated in animal experiments but also in human studies where the intake of fructose has been great, about 200-250g/dygn or> 20% E, together with an energy surplus.
The big problem is, as usual, energy surplus, which means that almost all the fat you eat is not burned but is stored in the liver and adipose tissue. An intake of 7.2 g fish oil (1.2 g EPA, 0.8 g of DHA) can improve blodfettrna we have high energy and fructose intake but does not affect insulin resistance. Fructose contribution to fat formation are also under extreme conditions, very small, about 3-7g of fat per day comes from fructose and glucose from the corresponding figure is about 1-3g fat per day in similar conditions. There is no difference in fat at an energy surplus with the extra addition of glucose, sucrose or fructose, but an extra addition of fat provides more fat than the equivalent amount from any carbohydrate source.
Fructose is best in small amounts so as to have time to fructose conversion to glucose or used directly as energy.
Fructose does not stimulate the release of leptin and does not inhibit grehlinproduktionen, which is saturation and the hunger hormone. Fructose saturating therefore worse than other carbohydrates such as. glucose or starch. This is mainly a problem when fructose is added to foods, for example. soda because soda is liquid and rich in energy, it has a very poor in terms of ability, which does not improve, if soft drink sweetened with fructose consideration.
A total intake of about 50-80g/dag or about 10-15E% is unlikely to have an adverse effect but perhaps only benefits. The energy surplus quantities can be limited to the lower recommendations. The energy deficit play the amount of fructose, a much smaller role because it can not be formed any surplus but you should probably still does not exceed 15E%.
In fruits and vegetables, about 20-50% of the carbohydrates from fructose but because fresh vegetables and fruits are high in water and therefore not as much carbohydrate as a whole as can the intake of fruits and vegetables to be high. Fructose content is about 0.1 to 7g / 100g which very well means that you can follow the Nordic nutrition recommendations about 600g fruit and vegetables per day and maximum 10E% from refined sugars, basically no matter what diet you follow.
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