One year after buying a stake in Nestle SA and watching his holding lose value, activist investor Dan Loeb is running out of patience.

Third Point, the activist fund Loeb runs, fired off a 34-page presentation during the weekend, demanding a far more radical transformation than the world’s largest food company has so far embraced. Accusing Nestle of a “muddled strategic approach’’ that threatens its future, Loeb said the company should sell its valuable stake in cosmetics company L’Oreal SA and consider splitting into three units to spur growth. He also said chairman Paul Bulcke is possibly obstructing change as the company needs more outsiders in management to shake up its “insular’’ culture.

With Nestle shares down about 10 percent since Loeb announced his $3.5 billion stake last year, chief executive Mark Schneider is facing more pressure after having resisted the activist’s biggest demands. While he’s made some acquisitions and announced a major buyback, he’s not engineered the wholesale makeover that Loeb is now asking for.

“We do not believe that the company is living up to this mandate today with its muddled strategic approach and we are concerned that Nestle does not fully appreciate the rapidly occurring shifts in consumer behavior that threaten its future,’’ Loeb said in a letter to the company’s board Sunday.

In a statement Monday afternoon, Nestle said it’s on track to meet its 2020 goals for margin improvement, operating profit, and structural cost savings. Without addressing Loeb directly, the company said its board and management “take all shareholders’ perspectives seriously and welcome their continued input.’’ The stock rose 0.70 percent Monday. L’Oreal fell 1.13 percent.

“There are too many examples of missed opportunities to claim that Nestle’s organization is well suited to today’s markets,’’ Loeb said in the Sunday letter. “We believe the company should simplify its overly complex organizational structure and split internally into three divisions organized around beverages, nutrition, and grocery to improve focus, agility, and accountability.’’

Loeb said the company hasn’t shown the necessary urgency since it released its own plan in September. Third Point also outlined its own strategy to improve Nestle in the presentation that calls for, among other things, divesting certain frozen-food brands and other products that don’t fit with its broader strategy.

“We believe Nestle should divest as much as 15 percent of sales either through sales, spinoffs, or other methods to better align the portfolio around key categories. It is clear that the company’s noncore financial stake in L’Oreal should be sold since the board remains unable to articulate a compelling long-term strategic rationale for its continued ownership,’’ he said.

Schneider has said that Nestle plans portfolio changes that will affect 10 percent of total sales. While selling the US chocolate business, Schneider has said the company is committed to the category in the rest of the world, where its business is more profitable. Nestle has repeatedly resisted calls to sell the L’Oreal stake.

Loeb faces obstacles in his attempt to spur Nestle to change, according to James Edwardes Jones, an analyst at RBC Capital Markets. He said Third Point’s stake, which is about 1 percent, may be too small to force quick changes.

Bulcke, the chairman, presided over a “long period of underperformance, seems too comfortable with the status quo, and may be holding up the pace and magnitude of change,’’ Loeb also wrote.

He said it’s “striking’’ that the board doesn’t include any members from outside with experience in the food and beverage industry.

Schneider, the first CEO to come from outside Nestle in almost a century, hasn’t made any major changes to top management. He has shown signs that the company no longer has sacred cows, however, with moves such as a plan to cut 500 jobs in Switzerland, the biggest restructuring the company has had in its home market.

Separately, The Wall Street Journal reported Monday that Nestle is in talks to buy a majority stake in Canada’s Champion Petfoods for more than $2 billion, citing people familiar with the matter.