Note: Lyle posted this on MWF...

Curr Opin Clin Nutr Metab Care.  2003 Nov; 6(6): 635-8.

The significance of protein in food intake and body weight regulation.

Westerterp-Plantenga MS.

Department of Human Biology, PO Box 616, 6200 MD Maastricht, The
Netherlands.
m.westerterp@hb.unimaas.nl

PURPOSE OF REVIEW: To highlight the underexposed but important role of
protein in food intake and body weight regulation. RECENT FINDINGS: Protein
plays a key role in food intake regulation through satiety related to
diet-induced
thermogenesis. Protein also plays a key role in body weight regulation
through its effect on thermogenesis and body composition. A high percentage
of
energy from dietary protein limits body weight (re)gain through its satiety
and
energy inefficiency related to the change in body composition. SUMMARY:
Protein
is more satiating than carbohydrate and fat in the short term, over 24 h and
in
the long term. Thermogenesis plays a role in this satiety effect, but the
role of
satiety hormones still needs to be elucidated. On the short-term 'fast'
proteins are
more satiating than 'slow' proteins, and animal protein induces a higher
thermogenesis than vegetable protein. In the longer term the higher
postabsorptive satiety and thermogenesis are sustained irrespective of the
protein source. High-protein diets affect body weight loss positively
only under ad-libitum energy intake conditions, implying also a decreased
energy
intake. Body composition and metabolic profile are improved. Additional
protein
consumption results in a significantly lower body weight regain after weight
loss, due to body composition, satiety, thermogenesis, and energy
inefficiency, while the metabolic profile improves. Implications from these
findings
are: for practice, recommendations for increasing the percentage of energy
from
protein while reducing energy intake; for clinical research, assessment of
the
paradox of increasing the percentage energy from a highly satiating
macronutrient; of the potential roles of protein in a negative and positive
energy balance;
assessment of possibilities of replacing dietary protein by effective amino
acids or peptides that may show a similar impact on body weight regulation.