The UK-based research and intelligence provider sets the total market value at $19.37 billion today, representing 50 per cent growth in the past five years.
The US and Japan account for the lion's share (37.6 and 35.5 per cent respectively), while the UK lags in third place with 11.3 per cent share, and Germany, Spain, Italy and France have a combined share of 12.5 per cent.
The bulk of the value is created by beverages, according to the report The Market for Performance Foods and Drinks. Performance foods are valued at just $1.2 billion in the countries under review.
Leatherhead's market intelligence business manager Susie Johnson told NutraIngredients.com that the food's poor show is probably due to market positioning. But since the energy bar market in the US is showing signs of maturity, it is hard to see how this will change radically over the next five years, says the report.
Moreover the energy cereals market seems to have fallen by the wayside. A few mainstream products were available five years ago but have either disappeared or are now marketed on a different platform.
As for drinks, there has been a steady shift in marketing towards the mainstream. Sports drinks - dominated by the US and Japan - still lead in volume terms. But in value they are coming under increasing pressure from energy drinks, which are priced higher.
Johnson agreed that so-called sports drinks are no longer aimed purely at sportspeople, but at sporty and health-conscious general consumers.
While these consumers may not need the levels of energy contained in the products if they are not doing a strenuous work out each day, they might need more energy as they are trying to fit more into the day.
"It is a different kind of energy," she said. "A key consumer concern is tiredness and products with energy may help to alleviate tiredness."
Mainstream soft drinks companies like Coca Cola and Pepsi-Co are big players in the market.
Both reported double-digit sales growth in the sales of their respective energy drink brands in Q3 2005 - as much as 28 per cent in the case of Cola Cola's Powerade. PepsiCo's rival product is Gatorade.
This week PepsiCo positioned itself for further growth in the functional drinks market with the acquisition of Ardea Beverage. Ardea's seven-strong NutriSoda line includes an 'Energize' product.
PepsiCo's diversification and faster action on health than Coca-Cola was reported in December to have taken it ahead of Coca-Cola in the market for the first time in 112 years.
The Ardea acquisition is clearly predicated by a desire to further outstep Coca-Cola in functional drinks. But as far as energy drinks go, acquisitions now seem atypical.
"Following a period of acquisition activity in the performance foods and drinks market in the 1990s and 2000s, companies are now tending to invest more heavily in consolidating and developing their product ranges and brands, both locally and globally," said Leatherhead's report.
Nutrition-interested multinationals such as Nestle and Danone also figure large, alongside pharmaceutical and dietetic companies like Glaxo SmithKline and national and local soft drinks companies.