Sign in to follow this  
DaDane

Protein

Recommended Posts

Jeg overvejer at købe mig noget protein pulver - men har en del spørgsmål

1) Har jeg brug for mere protein?

Hvor meget protein har jeg brug for? Jeg drikker en DEL mælk (>1 L pr. dag - skummetmælk. Ved godt at lactosen sikkert ikke er alt for perfekt, men jeg skal have min mælk. Kun ekstremt gode grunde kan få mig til at droppe den)

2) Overskydende protein (skulle der være noget) - kan det omdannes til fedt (Badr)

Jeg har hørt og kroppen kun opmagasinere fedt. Sukker kan omdannes til fedt men kun meget vanskeligt og protein kan slet ikke bruges til "brændstof" - dvs. det kan kun meget vanskeligt ændres til kulhydrat og endnu vanskeligere til fedt. Dog har jeg også hørt at "det er lige meget. Det er antal kalorier der tæller". Så hvis nogen kan belyse dette emne ville det være lækkert

3) Er der forskel på protein

Er der reel forskel på valleprotein, design protein og hvad det nu hedder alt sammen

4) Er der forskel på mærkerne

Er der reel forskel på om hvilket mærke det er?

5) Hvordan bruges det

Hvad blandes det op i - gode "opskrifter". Hvornår er det optimalt at tage det m.m.

Share this post


Link to post
Share on other sites
1) Har jeg brug for mere protein?
umuligt at svare på når jeg ikke aner hvad & hvor meget du spiser til dagligt!
2) Overskydende protein (skulle der være noget) - kan det omdannes til fedt

Ja! hvis du er i kalorieoverskud

3) Er der forskel på protein Er der reel forskel på valleprotein, design protein og hvad det nu hedder alt sammen

Ja - men betyder det noget for os der spiser 2+ gram protein pr. kg kropsvægt ? Nej!

Edited by -Anders-

Share this post


Link to post
Share on other sites

Enig med Anders i de 3 første.

4) Er der forskel på mærkerne
Ja, nogen er dyre andre er ikke. Indholdsmæssigt er der meget lille forskel - kig på udvindingsmetoden samt proteinindholdet, det giver normalt en god basis for sammenligning af priser.
5) Hvordan bruges det

Geez, vand virker fint.. mælk er godt.. havregryn, bær eller dextrose for tilføjelse af kulhydrater.. skyes the limit ;)

Share this post


Link to post
Share on other sites
Sukker kan omdannes til fedt men kun meget vanskeligt
Det passer simpelt hen ikke. Det er noget forfærdeligt vås, som bla. Arne Astrup har været med til at proklamere. Hvis dit energioverskud er stort nok, så omdannes kulhydrater ganske let til fedt, via de novo lipogenese. Der er flere undersøgelser som understøtter dette. Det er klart, at består ens diæt af meget store mængder fedt, så vil det være fedtet der bliver lagret. Men består ens diæt af meget sparsomme mængder fedt, men meget store mængder kulhydrater, som skaber et solidt kalorieoverskud, så vil kulhydraterne bliver omdannet til fedt via de novo lipogenese. Det er blandt andet forklaringen på hvorfor amerikanerne bliver federe og federe, til trods for at alt derovre er low-fat, non-fat osv. Budskabet om at man bare kan spise igennem, bare man spiser fedt-fattigt, er totalt vanvittigt. Det er antallet af kalorier som er afgørende. Ved kalorieoverskud kan alt lagres, ligegyldigt om det er fedt, protein eller kulhydrater.
protein kan slet ikke bruges til "brændstof

Dette passer heller ikke. Alle aminosyre, med undtagelse af leucine og lysin, kan bidrage til dannelsen af glucose, via den biokemiske proces som hedder gluconeogenese.

Thomas

Share this post


Link to post
Share on other sites

Thomas J - har du eventuelt et link eller noget til nogen af de undersøgelser, der viser at kulhydrat omdannes til fedt. Jeg kender en medeciner der nægter at tro på det, så jeg vil gerne kunne smide nogle facts i hovedet på ham... ;) ;) B)

Share this post


Link to post
Share on other sites

Selv Arne Astrup har trukket i land mht. "sukker feder ikke", under undskyldning af at det var hvad forskningen sagde dengang (under massiv sponsorering fra Danisco).. snak om bias i undersøgelserne!

Faktisk forbløffende hvad man kan komme afsted med som prof. i ernæring uden at der kommer alvorligere konsekvenser... sidenhen har der været en lille ting med Letigen, og sidst mht. Speasy - integritet er en god ting :(

Share this post


Link to post
Share on other sites

Vi har haft diskussionen før, så links til undersøgelserne må ligge et eller andet sted i arkivet. Men jeg skal nok poste dem, hvis jeg kan finde dem frem igen.

Thomas

Share this post


Link to post
Share on other sites

Her er et par undersøgelser du måske kan bruge til noget.....

Postprandial de novo lipogenesis and metabolic changes induced by a high-carbohydrate, low-fat meal in lean and overweight men.

Marques-Lopes I, Ansorena D, Astiasaran I, Forga L, Martinez JA.

Departments of Physiology and Nutrition and of Food Science, University of Navarra, Pamplona, Spain.

BACKGROUND: Adjustments of carbohydrate intake and oxidation occur in both normal-weight and overweight individuals. Nevertheless, the contribution of carbohydrates to the accumulation of fat through either reduction of fat oxidation or stimulation of fat synthesis in obesity remains poorly investigated. OBJECTIVE: The objective of this study was to assess the postprandial metabolic changes and the fractional hepatic de novo lipogenesis (DNL) induced by a high-carbohydrate, low-fat meal in lean and overweight young men. DESIGN: A high-carbohydrate, low-fat meal was administered to 6 lean and 7 overweight men after a 17.5-h fast. During the fasting and postprandial periods, energy expenditure (EE), macronutrient oxidation, diet-induced thermogenesis, and serum insulin, glucose, triacylglycerol, and fatty acids were measured. To determine DNL, [1-13C]sodium acetate was infused and the mass isotopomer distribution analysis method was applied. RESULTS: After intake of the high-carbohydrate meal, the overweight men had hyperinsulinemia and higher fatty acid and triacylglycerol concentrations than did the lean men. The overweight group showed a greater EE, whereas there was no significant difference in carbohydrate oxidation between the groups. Nevertheless, the overweight men had a marginally higher protein oxidation and a lower lipid oxidation than did the lean men. DNL was significantly higher before and after meal intake in the overweight men and was positively associated with fasting serum glucose and insulin concentrations. Furthermore, postprandial DNL was positively correlated with body fat mass, EE, and triacylglycerol. CONCLUSION: After a high-carbohydrate, low-fat meal, overweight men had a lower fat oxidation and a higher fractional hepatic fat synthesis than did lean men.

Effects of isoenergetic overfeeding of either carbohydrate or fat in young men.

Lammert O, Grunnet N, Faber P, Bjornsbo KS, Dich J, Larsen LO, Neese RA, Hellerstein MK, Quistorff B.

Department of Sports Sciences and Clinical Biomechanics, Faculty of Health Sciences, University of Southern Denmark, Denmark.

Ten pairs of normal men were overfed by 5 MJ/d for 21 d with either a carbohydrate-rich or a fat-rich diet (C- and F-group). The two subjects in each pair were requested to follow each other throughout the day to ensure similar physical activity and were otherwise allowed to maintain normal daily life. The increase in body weight, fat free mass and fat mass showed great variation, the mean increases being 1.5 kg, 0.6 kg and 0.9 kg respectively. No significant differences between the C- and F-group were observed. Heat production during sleep did not change during overfeeding. The RQ during sleep was 0.86 and 0.78 in the C- and F-group respectively. The accumulated faecal loss of energy, DM, carbohydrate and protein was significantly higher in the C- compared with the F-group (30, 44, 69 and 51% higher respectively), whereas the fat loss was the same in the two groups. N balance was not different between the C- and F-group and was positive. Fractional contribution from hepatic de novo lipogenesis, as measured by mass isotopomer distribution analysis after administration of [1-(13)C]acetate, was 0.20 and 0.03 in the C-group and the F-group respectively. Absolute hepatic de novo lipogenesis in the C-group was on average 211 g per 21 d. Whole-body de novo lipogenesis, as obtained by the difference between fat mass increase and dietary fat available for storage, was positive in six of the ten subjects in the C-group (mean 332 (SEM 191)g per 21 d). The change in plasma leptin concentration was positively correlated with the change in fat mass. Thus, fat storage during overfeeding of isoenergetic amounts of diets rich in carbohydrate or in fat was not significantly different, and carbohydrates seemed to be converted to fat by both hepatic and extrahepatic lipogenesis.

PMID: 11029975 [PubMed - indexed for MEDLINE]

De novo lipogenesis in humans: metabolic and regulatory aspects.

Hellerstein MK.

Department of Nutritional Sciences, University of California at Berkeley, 94270-3104, USA.

The enzymatic pathway for converting dietary carbohydrate (CHO) into fat, or de novo lipogenesis (DNL), is present in humans, whereas the capacity to convert fats into CHO does not exist. Here, the quantitative importance of DNL in humans is reviewed, focusing on the response to increased intake of dietary CHO. Eucaloric replacement of dietary fat by CHO does not induce hepatic DNL to any substantial degree. Similarly, addition of CHO to a mixed diet does not increase hepatic DNL to quantitatively important levels, as long as CHO energy intake remains less than total energy expenditure (TEE). Instead, dietary CHO replaces fat in the whole-body fuel mixture, even in the post-absorptive state. Body fat is thereby accrued, but the pathway of DNL is not traversed; instead, a coordinated set of metabolic adaptations, including resistance of hepatic glucose production to suppression by insulin, occurs that allows CHO oxidation to increase and match CHO intake. Only when CHO energy intake exceeds TEE does DNL in liver or adipose tissue contribute significantly to the whole-body energy economy. It is concluded that DNL is not the pathway of first resort for added dietary CHO, in humans. Under most dietary conditions, the two major macronutrient energy sources (CHO and fat) are therefore not interconvertible currencies; CHO and fat have independent, though interacting, economies and independent regulation. The metabolic mechanisms and physiologic implications of the functional block between CHO and fat in humans are discussed, but require further investigation.

Publication Types:

· Review

· Review, Tutorial

PMID: 10365981 [PubMed - indexed for MEDLINE

Thomas

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

Sign in to follow this